Iran nuclear deal divides U.S., world leaders

World leaders are hailing a major victory for diplomacy with the signing of a "historic" deal to curb Iran's nuclear ambitions in exchange for relief from crippling economic sanctions. 

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While the so-called P5 Plus 1 leaders — the United States, France, China, Russia, Britain and Germany — emerged from the meeting rooms of Vienna with a unanimous agreement Tuesday, reaction around the world has been divisive:

United States

In a public address on Tuesday morning, U.S. President Barack Obama said the deal is "not built on trust; it is built on verification."

Obama made a huge gamble in choosing to pursue negotiations with Iran, enduring taunts from Republican opponents in Congress over what they call his "weak" leadership.

After years of slow-bubbling, tough negotiations, the agreement has to jump a final hurdle in the U.S. Lawmakers in Congress must review and approve the Joint Comprehensive Plan of Action — leaving lots of room for heated rhetoric ahead of a decision on whether Iran will be folded back into the international community. However, Obama threatened to veto any legislation that would get in the way of the deal's implementation.

"We do not have to accept an inevitable spiral into conflict. And we certainly shouldn't seek it.  And precisely because the stakes are so high, this is not the time for politics or posturing. Tough talk from Washington does not solve problems. Hard-nosed diplomacy, leadership that has united the world's major powers offers a more effective way to verify that Iran is not pursuing a nuclear weapon."

As expected, the U.S. Republican Party is harshly criticizing the nuclear agreement. 

Speaker of the House of Representatives John Boehner said the deal emboldens the world's "largest sponsor of terror."

"Instead of stopping the spread of nuclear weapons in the Middle East, this deal is likely to fuel a nuclear arms race around the world," Boehner said in a statement.

He said the House would examine the agreement closely, promising to "fight a bad deal that is wrong for our national security and wrong for our country."

Even some members of Obama's own Democratic Party are skeptical.

Democrats, including Connecticut Senator Chris Murphy, have cautiously congratulated the president's efforts, but maintained they would closely review the agreement in the coming weeks.

Iran

Iranian President Hassan Rouhani has dismissed claims that the Islamic Republic sought to make atomic weapons under its nuclear program.

Speaking live in a nationwide televised address Tuesday, Rouhani said: "Iran has never sought to manufacture a nuclear weapon and will never seek to manufacture a nuclear weapon."

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He added: "The whole world knows very well that manufacturing a nuclear bomb ... is considered forbidden."

The comment came during a speech in which Rouhani sought to appease hard-liners about the nuclear deal's merits.

Israel

Israel has been the most vocal and active opponent of negotiations with Iran, saying any nuclear deal and lifting of sanctions would pose an existential threat to the country. Iranian officials repeatedly have threatened to destroy Israel in the past. Iran also backs militant groups that attack it. 

• Israel's Benjamin Netanyahu condemns Iran nuclear deal as 'historic mistake'

Israeli Prime Minister Benjamin Netanyahu said it is a "stunning historic mistake."

An accord with Iran, he said on Tuesday, will allow it "to continue to pursue its aggression and terror in the region."

Canada

Defence Minister Rob Nicholson said Canada appreciates the efforts made by the P5 Plus 1 countries to reach the agreement, but will "judge Iran by its actions, not its words."

Nicholson said in a statement released Tuesday that the government "will continue to support the efforts of the International Atomic Energy Agency to monitor Iran's compliance with its commitments.

"Iran continues to be a significant threat to international peace and security owing to the regime's nuclear ambitions, its continuing support for terrorism, its repeated calls for the destruction of Israel, and its disregard for basic human rights," he said, adding that Canada will examine the deal further before taking any specific action.

Britain

British Prime Minister David Cameron said "persistent diplomacy and tough sanctions" delivered a "historic deal with Iran."

"A deal which secures our fundamental aim — to keep Iran from developing a nuclear weapon — and that will help to make our world a safer place." 

Saudi Arabia

The Gulf state, which has been a regional rival to Iran for decades, said it supported an agreement to stop Tehran gaining nuclear weapons, but emphasized the importance of a strict inspections regime and the ability to reimpose sanctions.

The comments, attributed to "an official source" by the state-run Saudi Press Agency, also stressed that sanctions relating to terrorism and violation of international arms treaties would remain intact. It was the first official Saudi reaction to the agreement between major powers and Tehran.

Russia

"The world heaved a sigh of relief today," Russian President Vladimir Putin said in a statement on the Kremlin's website. 

"Despite the attempts to validate any scenarios based on the use of force, the parties to the negotiations made a choice in favour of stability and co-operation, which will be reflected in a corresponding UN Security Council resolution." 

Russia wants to expand military co-operation and arms sales with Tehran, including the long-delayed transfer of S-300 advanced air defence systems. As such, Putin concluded his country "will do everything in its power to ensure the full implementation of the Vienna agreements."

Iraq

The spokesman for Iraqi Prime Minister Haider al-Abadi says the nuclear deal will be "a catalyst for regional stability."

Saad al-Hadithi told The Associated Press that the landmark agreement is "an important step" and will lead to better unity in the fight against terrorism.

A U.S.-led coalition is conducting airstrikes in Iraq against the Islamic State of Iraq and Syria while neighbouring Iran provides extensive logistical support on the ground. Despite their shared interests in defeating ISIS and Syria, coalition nations have not worked directly with Iran, Iraq's biggest ally, even while negotiations were underway in Vienna.

United Nations

Secretary General Ban Ki-moon said Tuesday the agreement is "testament to the value of dialogue," and admired the "courage of the leaders" who approved the deal. 

Agencies and inspectors with the world body are responsible for ensuring that Iran complies with restrictions laid out in the accord and the UN affirmed its commitment to fully co-operate with all parties.

"I hope — and indeed believe — that this agreement will lead to greater mutual understanding and cooperation on the many serious security challenges in the Middle East.  As such it could serve as a vital contribution to peace and stability both in the region and beyond," said Ban.