Israeli Prime Minister Benjamin Netanyahu told a joint session of Congress that removing economic sanctions on Iran would lead to terrible results. Here are highlights from his speech. (Sarah Parnass/The Washington Post)

In a rousing speech before Congress punctuated by more than 40 bursts of applause, Israeli Prime Minister Benjamin Netanyahu on Tuesday assailed the Obama administration’s nuclear negotiations with Iran, asserting that the United States was on the verge of making “a bad deal.”

Though he said he was “grateful” for all President Obama has done for Israel, Netanyahu went on to excoriate the administration for what he called its failure to insist on terms tough enough or enduring enough to prevent Iran from acquiring a nuclear weapon. “It doesn’t block Iran’s path to the bomb; it paves Iran’s path to the bomb,” Netanyahu said.

The speech before a joint meeting of Congress gave the Israeli prime minister a rare platform to confront a president with whom he has shared mostly animosity. And it gave Netanyahu a chance to try to stop or alter the course of negotiations that are reaching a critical juncture. Obama has said that if Iran does not agree to the outline of an accord by the end of March, then further talks will be pointless, but he is still pressing for a strategic breakthrough.

Netanyahu made the most of the opportunity, invoking the Constitution, Moses and the Holocaust to argue that the United States and Israel should stand fast to block Iran from gaining weapons. He hailed Holocaust survivor and Nobel Peace Prize winner Elie Wiesel, who was in the gallery, and said, “I wish I could promise you, Elie, that the lessons of history have been learned.”

[Read the complete transcript of Netanyahu’s address to Congress]

Many members of Congress leapt to their feet to applaud Israeli Prime Minister Benjamin Netanyahu during his address Tuesday. Here are the top 10 lines. (Associated Press)

Aware of the danger that Congress would be persuaded to try to scuttle a deal with Iran, the White House responded quickly.

Speaking in the Oval Office alongside Defense Secretary Ashton B. Carter, Obama defended the nuclear talks with Iran and said Netanyahu did not offer any “viable alternatives.” Obama, who had been on a conference call discussing Ukraine with European leaders during Netanyahu’s speech, said he read a transcript and that “there was nothing new” in it.

“The alternative that the prime minister offers is no deal, in which case Iran will immediately begin once again pursuing its nuclear program, accelerate its nuclear program, without us having any insight into what they’re doing, and without constraint,” Obama said.

Obama also urged Congress to “wait until there’s actually a deal on the table” before evaluating the plan.

Netanyahu’s speech marked the climax of controversy that began six weeks ago when he accepted an invitation from House Speaker John A. Boehner (R-Ohio) to address Congress; Boehner sidestepped the usual protocol of consulting with the president and Democrats in Congress before issuing the invitation a day after Obama’s State of the Union address. Critics say the plan was hatched to serve partisan purposes in the United States as well as in Israel, where voters go to the polls in two weeks.

Netanyahu used the address Tuesday to paint Iran as a sponsor of terrorism that is marching across the Middle East and determined to realize its nuclear ambitions. Netanyahu said the country poses a “grave threat” to Israel and the world.

“This is a bad deal. A very bad deal. We are better off without it,” he said. “Why should Iran’s radical regime change for the better when it can enjoy the best of both worlds? Aggression abroad, prosperity at home?”

After reading a transcript of Benjamin Netanyahu's remarks to Congress, President Obama said that the Israeli prime minister did not offer "any viable alternatives" to a nuclear deal with Iran. (AP)

Secretary of State John F. Kerry and Iranian Foreign Minister Mohammad Javad Zarif talked for more than five hours in Montreux, Switzerland, on Tuesday ahead of a March 24 deadline on the framework for a nuclear deal. Neither hinted about how talks were progressing.

Netanyahu said that demands should be tougher and urged that “if Iran threatens to walk away from the table, call their bluff.” He said tough economic sanctions would bring them back to talks.

A Reuters interview with Obama on Monday and remarks from other officials have provided outlines of the terms being negotiated with Iran by the United States and five other world powers. As a condition for the talks, Iran agreed to eliminate its stockpile of highly enriched uranium needed for a nuclear weapon.

The terms being negotiated would require inspections by the International Atomic Energy Agency, limits on the type and number of centrifuges needed for enrichment, and full replies to IAEA questions about past military activities. The terms would also require Iran to continue turning uranium into rods used for civilian nuclear power or sending the material to Russia. The goal is to establish at least one year of “breakout time,” the length of time Iran would need to develop a weapon if cooperation was to break down.

The United States initially asked Iran to agree to limits on its nuclear program lasting 15 to 20 years, while Iran asked for a five-to-10-year period. Obama said the duration would have to be ­“double-digit.” After that period, say people familiar with the deal, Iran would still have to comply with IAEA guidelines and allow unfettered inspections by the agency. But limits on centrifuges could end.

“It’s not as though they are free to develop nuclear weapons” afterward, said Robert Einhorn, an arms control export at the Brookings Institution who previously advised the State Department under Obama. “There is still intrusive verification under additional protocols of the IAEA, so we would be in a better position than today to detect movement toward nuclear weapons and there would still be the option of military action. It’s not as though it’s a free pass to nuclear weapons after expiration.”

Even those terms could be too stringent for Iran. In an interview published Tuesday by the semiofficial Iranian news agency Fars, Zarif called the American demand that Iran freeze its nuclear activities for at least a decade “unacceptable.” He added, “Iran will not accept excessive and illogical demands.”

Netanyahu said a deal would only “whet Iran’s appetite” for more nuclear material. Playing off the title of an Ernest Hemingway novel, he said: “This deal won’t be a farewell to arms. It would be a farewell to arms control.”

The prime minister also spoke of the Jewish holiday Purim, which begins Wednesday night. It celebrates the biblical book of Esther, which describes a plot by a high-ranking member of the Persian empire to kill the Jews; the plot is foiled by Queen Esther, who is Jewish.

“Today the Jewish people face another attempt by yet another Persian potentate to destroy us,” Netanyahu said.

He warned against viewing Shiite Iran as an ally against Sunni extremists in the Islamic State militant group, declaring that “the enemy of your enemy is your enemy.” And he cited threats by Iranian leader Ayatollah Ali Khamenei to “annihilate” Israel and the implication of Iran — and its “tentacles of terror” — in various attacks around the world.

Later in the Oval Office, Obama said he agrees with Netanyahu that Iran is a dangerous regime that has repeatedly threatened Israel and that “no one can dispute” that Iran has used anti-Semitic language against Israelis.

“But on the core issue, which is how do we prevent Iran from obtaining a nuclear weapon, which would make it far more dangerous and would give it scope for even greater action in the region, the prime minister didn’t offer any viable alternatives,” Obama added.

A variety of notables attended the speech. Former House speaker Newt Gingrich (R-Ga.), billionaire Sheldon Adelson and former senator Joseph I. Lieberman (I-Conn.) sat in the speaker’s suite.

Across the way in another VIP suite sat business magnate and New England Patriots owner Robert Kraft and former senator Norm Coleman (R-Minn.). On the House floor, where former members are still allowed as long as they are not lobbyists, were television host Joe Scarborough, Ohio Gov. John Kasich (R) and former congresswoman Michele Bachmann (R-Minn.). Bachmann positioned herself to be the first person in the House chamber to greet Netanyahu upon entry.

Nearly a quarter of congressional Democrats did not attend the speech, citing the politicization of the address and the disrespect they felt Netanyahu and Boehner had shown the president. Others attended reluctantly.

House Minority Leader Nancy Pelosi (D-Calif.), who left the chamber as Netanyahu was saying goodbyes, said in a statement that she was “saddened by the insult to the intelligence of the United States as part of the P5 +1 nations, and saddened by the condescension toward our knowledge of the threat posed by Iran and our broader commitment to preventing nuclear proliferation.”

Sen. Dianne Feinstein (D-Calif.) said on CNN that Netanyahu “clearly . . . doesn’t like what the deal is. What he didn’t say was what would happen if there was no deal” or what would happen if the United States’ negotiating partners — Britain, France, Germany, Russia and China — “all agreed and the United States did not.”

[Decrying ‘insult,’ some Democrats seethe after Netanyahu address]

Erel Margalit, a leading Labor Party candidate in the coming Israeli elections, was in the United States on Tuesday. “In three weeks, we’ll have a chance to set a new path for Israel,” he said. “Hopefully we can not just define ourselves by the threat we face but by the opportunities.”

He said the Labor Party shared Netanyahu’s concerns about Iran’s nuclear program, but he said, “We want to work with the administration rather than have a showdown with it.”

Carol Morello in Montreux contributed to this report