Crimea’s parliament on Monday voted to break away from Ukraine and join the Russian Federation, a day after a huge majority of the peninsula’s voters chose that option in a referendum that was condemned as a sham in Washington and across Europe.

The United States and European nations promptly slapped financial sanctions and a travel ban on Russian and Ukrainian authorities responsible for a Russian push into Crimea and support for the referendum. The current Ukraine government said it was call up military reservists and planning a splurge of defense spending to beef up its military in case of further Russian efforts to take territory.

The vote in Crimea’s regional parliament now puts the onus on Russia to decide whether, and when, to absorb the territory that has been occupied by Russian forces since late last month. Russian legislators have suggested it is only a matter of time.

Crimean election spokesman Mikhail Malyshev said Monday that 83.1 percent of the eligible population voted Sunday and that the final result was 96.77 percent in favor of joining Russia and 2.51 percent against.

A delegation of 50 members from the Crimean parliament was planning to head to Moscow on Monday afternoon to formally present their request for annexation, as Russian officials begin crafting their response. President Vladimir Putin will speak to a joint session of Russia’s parliament about the situation in Crimea on Tuesday afternoon, Ivan Melnikov, a deputy speaker of the lower house, told reporters Monday. The lower house, or State Duma, plans to consider a request for annexation by Friday.

The Post's Carol Morello shows scenes from Sevastopol, Ukraine on Mar. 16, 2014. (Carol Morello & Sandi Moynihan/The Washington Post)

Once the legislation has passed, it will be up to Putin to decide how quickly to act on it. Actual accession could be in the works for months, analysts said.

The Russian Foreign Ministry posted a statement Monday elaborating on proposals, presented over the last several days to the United States and other countries, that could keep Ukraine intact.

It calls for a “contact group” of nations that would be required to carry on a dialogue with Kiev and Moscow, as Ukraine draws up a new constitution. Russia wants Ukraine to become a federal republic, with each region enjoying a considerable amount of autonomy on language and finances. That is a notion that the current government in Kiev totally opposes. It fears that it would lead to the break-up of the country, with the eastern regions moving closer to Russia against the wishes of the western regions. It would also deny Kiev a large share of the taxes that it currently collects.

Russia also wants Ukrainian guarantees that it would remain a neutral nation — and a United Nations Security Council Resolution to enshrine that neutrality. But the plan now being circulated also involves the European Union more deeply in settling the crisis. As first presented, the Russian plan included no explicit role for the E.U.

The proposal began circulating Sunday, as it became obvious that the Crimean referendum was going ahead and that E.U. foreign ministers would be meeting Monday to decide on sanctions against Russia.

The White House and Western governments rejected the referendum, conducted as thousands of Russian troops occupied the peninsula. Ukraine’s interim prime minister, Arseniy Yatsenyuk, dismissed the vote as a “circus” under the “stage direction” of Moscow.

A vote in favor of seceding from Ukraine was widely expected; ethnic Russians make up 60 percent of Crimea’s population, and the region has deep historical ties to Russia. But the vote may only complicate the biggest standoff between Russia and the West since the end of the Cold War and increase security fears in the rest of Ukraine and in other former Soviet states.

Tensions rose elsewhere in Ukraine on Sunday. In the eastern city of Donetsk, thousands of pro-Russian demonstrators rallied in support of following Crimea’s lead and holding a referendum on joining Russia. Clusters of protesters stormed two government offices. Pro-Russian activists in Kharkiv, another troubled city in Ukraine’s east, charged into a cultural center and burned Ukrainian-language books while several thousand Moscow sympathizers marched in the southern city of Odessa, according to the Reuters news agency.

Shortly before midnight in the Crimean regional capital, Simferopol, with tens of thousands of people jamming Lenin Square and nearby streets, Crimean political leaders announced the preliminary vote totals. Fireworks exploded overhead while a male chorus sang the Russian national anthem from a giant stage and people screamed and hugged one another.

In the Crimean Peninsula’s other major city, Sevastopol, local vote results were announced on a concert stage in the biggest square.

Dmitri Belik, head of the city council, told the cheering crowd, “Sevastopol, we are in Russia! Thank you, citizens of Sevastopol, we did it with your help, and nobody is going to kick us out.”

The vote marked the latest dramatic political development in Ukraine since Viktor Yanukovych, its pro-Russian president, abruptly decided in November to break off talks on an accord with the European Union and move closer to Russia. This ignited mass protests, which eventually prompted him to flee the country. Parliament named a pro-Western government in his place. Within days, Moscow sent troops into the Crimean Peninsula, where Russia has a major naval base.

In Crimea, residents began celebrating hours before polls closed. In Sevastopol, drivers with Russian flags flying from their car windows sped through the city honking horns.

“This is a dream come true,” said Irina Karbuk, a housewife whose husband was waving a Russian flag in Nakhimov Square. “We already are in Russia.”

Elevated Russian presence

As voting was about to commence, Russia’s military presence on the peninsula increased dramatically. A Ukrainian Defense Ministry official said that about 50 military trucks carrying diesel generators were observed late Saturday on the road to Sevastopol. About 100 armored vehicles and trucks were seen heading toward a military airport near Dzhankoy in northern Crimea, said Vladislav Seleznyov, a ministry spokesman.

Acting Ukrainian Defense Minister Ihor Tenyukh said Sunday that Russia had sharply elevated its troop presence in Crimea in recent days, bringing the total to 22,000. Tenyukh told the Interfax news agency that under basing agreements, Russia is limited to 12,500 troops in Crimea.

The United States and most Western countries have said that they will not recognize the results of the referendum, citing the Russian military occupation that began a few weeks ago and the crisis conditions under which the vote was called.

Even as Crimea voted, diplomacy appeared to shift into high gear. President Obama and Putin spoke by phone. While Putin defended the referendum as legitimate, a Kremlin statement said the two presidents agreed to “work together” to help maintain calm in Ukraine.

In an earlier phone call between Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John F. Kerry, Lavrov insisted that the referendum was legitimate but also said that “the results should be the starting point in determining the future of the peninsula,” according to a statement issued Sunday by the Russian Foreign Ministry.

In the State Department’s version of the call, a senior official said Kerry had reaffirmed that the U.S. government will not recognize the outcome of the referendum. Kerry, the official said, “raised strong concerns” about Russian military activity near the Crimean border and “continuing provocations in eastern cities in Ukraine.”

But the Russian and U.S. statements appeared to provide a flicker of optimism that the situation might be resolved without Russian annexation of Crimea.

Englund reported from Moscow. Witte reported from London.