Responding to Russia’s latest moves to formalize its annexation of Crimea, President Obama on Thursday announced new sanctions against Moscow and authorized possible future penalties against “key sectors of the Russian economy.”

Russia promptly retaliated by banning nine U.S. lawmakers and officials from entering the country. The list of banned Americans includes Senate Majority Leader Harry M. Reid (D-Nev.), House Speaker John A. Boehner (R-Ohio), Sen. John McCain (R-Ariz.) and three top Obama aides, the Russian Foreign Ministry said. McCain lamented sarcastically that his spring vacation in Siberia was now “off.”

The announcements came after the lower house of the Russian parliament voted Thursday to admit Crimea and the metropolitan region of Sevastopol into the Russian Federation, putting some of the final procedural touches on Moscow’s controversial takeover of the Crimean Peninsula from Ukraine.

In Washington, Obama said he was ordering new sanctions against Russia in response to what he called Crimea’s “illegal” secession referendum and Russia’s “illegitimate move” to annex Crimea.

“The United States is today moving . . . to impose additional costs on Russia,” Obama said before embarking on a trip to Florida. He said more top Russian officials will be subject to sanctions, as well as other individuals and a bank known for providing “material support” to the Russian leadership.

President Obama said Thursday before leaving for Florida that the U.S. government would expand sanctions on Russian individuals and authorize future sanctions for sectors of the Russian economy. The president predicted these measures could have an effect on the global economy. (The Associated Press)

Obama added that he “signed a new executive order today that gives us the authority to impose sanctions not just on individuals but on key sectors of the Russian economy.” He did not immediately elaborate on which sectors might be targeted, but he noted: “This is not our preferred outcome. These sanctions would not only have a significant impact on the Russian economy, but could also be disruptive to the global economy.”

A fact sheet released by the Treasury Department listed 20 individuals and the Bank Rossiya as targets of the additional sanctions. Eleven people — including seven Russians — were named on a sanctions list issued earlier this week.

The individuals and the bank are being punished in connection with the annexation of Crimea. The new executive order that Obama signed separately authorizes the Treasury, if Obama so decides in the future, to impose sanctions against additional Russian entities — which he described as constituting key sectors of the economy — in the event that Russia takes further action such as invading the rest of Ukraine.

In Crimea, Ukrainian troops continued to face threats Thursday, as a group of armed men boarded a Ukrainian ship in the Black Sea port of Sevastopol.

Vladislav Seleznyov, a Ukrainian Defense Ministry spokesman, said about 20 gunmen boarded the anti-submarine corvette Ternopol shortly after sunset Thursday and seized it, using flash grenades. There were no reported injuries.

Among those on the new sanctions list are government and business leaders who have been close to Russian President Vladimir Putin, some for many years. They include some of the richest men in Russia, as well as one Russian who is in the oil-trade business in Switzerland.

Connections to St. Petersburg, Putin’s home town, abound. The list targets several of the business leaders who have profited the most during Putin’s years in power through their connections to him.

The list includes key officials such as Sergei Naryshkin, speaker of the lower house of parliament, and Sergei Ivanov, head of the presidential administration, as well as influential Russians in the banking and business communities. Among them is Yuri Kovalchuk, an old Putin friend from St. Petersburg who is known as “Putin’s banker.”

Kovalchuk and another person on the list, Putin aide Andrei Fursenko, are owners of Bank Rossiya, the sanctioned bank.

Bank Rossiya was described as having $10 billion in assets and as handling financial transactions for many senior Russian officials.

Long-time Putin associates Arkady and Boris Rotenberg also were named. A senior U.S. official pointed out that the St. Petersburg-based brothers were close to the center of power, receiving $7 billion in contracts connected to the Sochi Olympics.

The senior Obama administration official described the targets as “senior government officials, cronies and a crony bank.”

Briefing reporters Thursday after Obama’s speech, the official took a stern tone. “We saw some bluster earlier in the week that sanctions would have no impact. I would suggest if they have any interest in doing business outside the U.S., they will have difficulty doing so.”

The bank will be frozen out of the dollar, and correspondent accounts with U.S. banks will be terminated, the official said, adding that sanctioned individuals “will be prevented from operating around the world to the greatest extent possible.”

The other Americans banned from entering Russia are Caroline Atkinson, deputy national security adviser for international economic affairs; presidential aides Daniel Pfeiffer and Benjamin Rhodes; Sen. Robert Menendez (D-N.J.), chairman of the Senate Foreign Relations Committee; Sen. Mary Landrieu (D-La.) and Sen. Daniel Coats (R-Ind.).

“We have warned repeatedly that using sanctions is a double-edged sword and will hit the United States back,” the Russian Foreign Ministry said in a statement posted on its Web site.

“Washington has been repeatedly assured that it is unacceptable and counterproductive to talk with our country in such a way,” it said. “However, the U.S. seems to continue believing blindly in the efficiency of such methods, taken from the arsenal of the past, and does not want to admit the obvious — in complete accordance with international laws and the U.N. charter, Crimean residents voted democratically for rejoining Russia. This decision can be liked or not, but it concerns reality, which has to be taken into account.”

The statement added: “There should be no doubts — we will respond adequately to every hostile attack.”

Foreign Minister Sergei Lavrov and Secretary of State John F. Kerry spoke again by phone Thursday about Ukraine, and Lavrov said the United States must stop “condoning” the activities of the right-wing Ukrainian group Right Sector and the Svoboda party, the ministry said in a separate statement.

“Lavrov stressed that the decision on Crimea’s reunification with Russia reflected the expression of the will of the absolute majority of its people, that it may not be reviewed and must be respected,” the statement said. Lavrov, it said, complained about “ongoing violence” by “ultranationalist and extremist forces,” who he claimed were targeting businessmen, journalists, dissenters, Russian speakers and “our compatriots.”

Responding to his inclusion in the ban, McCain said in a statement: “I guess this means my spring break in Siberia is off, my Gazprom stock is lost, and my secret bank account in Moscow is frozen. Nonetheless, I will never cease my efforts on behalf of the freedom, independence, and territorial integrity of Ukraine, including Crimea.”

Menendez said in a statement: “President Putin’s military invasion and annexation of Crimea is brutal, totally unacceptable, and sadly returns us to a period of Cold War aggression and hostility. It doesn’t have to be this way, but if standing up for the Ukrainian people, their freedom, their hard earned democracy, and sovereignty means I’m sanctioned by Putin, so be it.”

The vote in Russia’s lower house, the State Duma, to annex Crimea was 443 to 1. The measure needed 300 votes to pass.

The lone Duma dissenter, Ilya Ponomaryov, later tweeted, “The best intentions have led us to a big political mistake: I vote against the war.”

[Meet the one Russian lawmaker who voted against annexing Crimea.]

The bill is scheduled to be taken up Friday by the upper house, the Federation Council, where expected approval will make Crimea officially part of the country under Russian law — despite the insistence of the United States, Europe and others that it remain part of Ukraine.

In Crimea on Thursday, Ukraine’s influence over the disputed region seemed visibly on the wane, with military bases now under the Russian flag and Ukrainian banks closed for the time being. The Ukrainian Defense Ministry said it was preparing a plan to withdraw its remaining troops and officials.

Still, there were hints of a potentially durable conflict, as both Europe and the United States pledged further financial sanctions against Russia, and officials in Kiev and Moscow talked of trade, visa and other penalties they might impose against each other.

Lavrov, testifying Thursday in favor of the bill in the Duma, warned Ukraine not to seize property located within its borders of the Russian state-owned energy giant, Gazprom. He said such a move would have negative consequences for Ukraine.

“I think that it is in no one’s interests to begin this battle,” he said. “This could lead to a quite complex chain reaction, from which I suppose Ukraine will not benefit.”

Lavrov said that he thought Ukraine’s threat to leave the Commonwealth of Independent States, a post-Soviet grouping, is essentially a “propaganda” ploy, but he added that Russia will do nothing to stop it if that’s what Ukraine wishes.

However, Russia’s sanitary service almost simultaneously announced that Ukrainian livestock will be barred from Russia if the country leaves the CIS.

The Foreign Ministry said in a statement posted on its Web site that it regrets Ukraine’s intention to require Russian visitors to obtain visas.

United Nations Secretary General Ban Ki-moon visited Putin in the Kremlin on Thursday and said he was deeply concerned about the Crimean crisis.

“We highly appreciate your efforts,” Putin said, before they began private talks.

European leaders on Thursday weighed additional sanctions against Russia, a day after Ukrainian troops were forced to abandon their bases in Crimea and prepared to evacuate the peninsula.

German Chancellor Angela Merkel told her parliament that Europe would expand the number of individuals punished with travel bans and asset freezes for their role in the Russian takeover of Crimea. But as European Union leaders prepared to meet in Brussels, there was little sign they would impose the sort of broader financial penalties that many analysts see as necessary to change Russian behavior.

U.S. officials have repeatedly emphasized their close consultation with Europe, and the announcement of initial sanctions early this week was coordinated with the allies.

The European Union on Monday imposed sanctions on 21 Russian and Ukrainian officials, and the United States announced sanctions the same day against 11 people — seven top Russian government officials and politicians and four Ukrainians, including ousted president Viktor Yanukovych and two Crimean separatist leaders.

Speaking from Brussels, interim Ukrainian Prime Minister Arseniy Yatsenyuk said Thursday that he did not believe Russia would stop at Crimea. “It’s crystal clear for us that Russian authorities will try to move further and escalate the situation in southern and eastern Ukraine,” Yatsenyuk told Bloomberg News.

In Crimea, meanwhile, the Ukrainian presence continued to ebb. Ukrainian banks were closed Thursday, with signs taped to the doors saying they no longer have authority to operate in Crimea because they are on foreign territory. They said they are making arrangements to reopen and that depositors will not lose their savings.

Leonid Polyakov, Ukraine’s deputy minister of defense, said a plan has been prepared to evacuate military families from Crimea, but the troops themselves have not yet been given orders.

Ukraine said Wednesday it would seek U.N. support in declaring Crimea a demilitarized zone so that its troops could be relocated to Ukraine proper, effectively acknowledging that it had lost the region despite vows it would never cede to Russia.

In the announcement, the secretary of Ukraine’s National Security and Defense Council, Andriy Parubiy, said his country would hold joint military exercises with the United States and Britain. He did not provide details, but a Pentagon spokesman in Washington said the annual multinational exercises were previously planned and will be held in the summer.

Parubiy also said Ukraine would leave the Commonwealth of Independent States, an alliance of 11 nations that were part of the Soviet Union before it broke up
in 1991. It is led by Russia, and Ukraine’s departure echoes steps taken by Georgia after two of its territories broke away in 2008 with the support of Moscow.

Russia’s storming of the Ukrainian military facilities in Crimea, and the positioning of forces outside another base, served as a tense reminder of how unresolved the situation remains in Crimea even as Russia declares its absorption of the region an established fact. Ukrainian troops largely gave way without resistance Wednesday, though tension may be building as they face an apparent choice of becoming Russian soldiers and sailors, or moving from Crimea and maintaining their allegiance to Kiev.

Russia is also unlikely to agree to the terms of a demilitarized zone, which would require it to withdraw troops from the region while Ukraine pulls its forces out.

Russia moved swiftly to step up its occupation of Crimea after Putin on Tuesday signed a treaty annexing the peninsula. Its most significant action was the takeover of the Ukrainian navy headquarters in Sevastopol, where pro-Russia militias and Russian regular troops stormed the base and checked Ukrainians at the gate as they left toting bags of personal belongings.

The Ukrainian rear admiral in command, Serhiy Haiduk, was taken out of the compound in a car, and Ukrainian officials charged that the Russians had taken him hostage.

Ukrainian President Oleksandr Turchynov on Wednesday gave Crimean authorities three hours to release Haiduk and stop harassing the Ukrainian military or face “appropriate measures.” The deadline passed without apparent action.

However, Haiduk was released Thursday morning, according to Turchynov’s office. Several pro-Ukrainian activists also were set free.

Branigin reported from Washington. Karen DeYoung in Washington and Carol Morello in Crimea contributed to this report.