US President Donald Trump on Friday announced the "decertification" of an international agreement that dropped sanctions against Iran in exchange for Tehran halting its nuclear program.

"The Iranian regime has committed multiple violations of the agreement," he said. "I am announcing today that we cannot and will not make this certification. We will not continue down a path whose predictable conclusion is more violence more terror and the very real threat of Iran's nuclear breakout."

Read more: What is the Iran nuclear deal?

Iran: US is against the Iranian people

After Trump's speech, Iranian President Hassan Rouhani said as long as his country's interests are preserved, Iran would remain committed to the nuclear deal. He also added that Tehran would double its efforts to build weapons for deterrence and expand its missile program, as permitted by the agreement.

"Today the United States is more than ever opposed to the nuclear deal and more than ever against the Iranian people," Rouhani said in a televised speech.

Though Trump did not put an immediate end to the agreement, he said he could terminate the deal at any time - and would do so in the event US Congress does not establish additional measures to ensure Iran's compliance. The US president also announced targeted sanctions against Iran's elite Islamic Revolutionary Guard Corps for "supporting terrorism."

The head of the UN nuclear watchdog said Iran was under the world's "most robust nuclear verification regime."

"The nuclear-related commitments undertaken by Iran under the JCPOA are being implemented," said Yukiya Amano, director general of the International Atomic Energy Agency.

Decision with Congress

Trump stopped short of pulling the US out of the nuclear deal and instead left that decision to Congress. Lawmakers now have 60 days to decide if they will reintroduce sanctions against Iran. However, they are not legally required to do so and could let the 60-day period expire without recourse.

The product of years of negotiations, the 2015 nuclear deal marked a major diplomatic victory for Germany, China, France, Russia, the UK, the European Union and the United States, which sought to limit Tehran's ability to develop a nuclear weapon.

However, since the agreement went into force in January 2016, the administration has changed in Washington. While still campaigning, Trump described the nuclear deal as "disastrous," and vowed to "dismantle" it. However, he had recertified the deal twice since assuming office in January.

Former US Secretary of State John Kerry, who negotiated the deal during Barack Obama's presidency, slammed Trump for his "dangerous" decision that is "creating an international crisis."

"It endangers America's national security interests and those of our closest allies," Kerry said, adding that it was up to the other signatories and Congress as "the adults in the room" to save the deal. 

Europe responds

The EU's foreign policy chief, Federica Mogherini, said after Trump's speech that the nuclear agreement cannot be renegotiated.

"It is not up to any single country to terminate it," Mogherini said.

Read more: Donald Trump and the Iran nuclear deal: A crisis in the making

Meanwhile, Germany, France and the UK issued a joint statement warning the US of its moves against the Iran nuclear deal after Trump's remarks.

"The nuclear deal was the culmination of 13 years of diplomacy and was a major step towards ensuring that Iran's nuclear program is not diverted for military purposes," said a statement from German Chancellor Angela Merkel, French President Emmanuel Macron and British Prime Minister Theresa May.

"Therefore, we encourage the US administration and Congress to consider the implications to the security of the US and its allies before taking any steps that might undermine the (accord), such as re-imposing sanctions on Iran lifted under the agreement."

Read more: EU rejects Donald Trump's attempt to dump Iran nuclear deal, saying it works

Regional adversaries

Israeli Prime Minister Benjamin Netanyahu, however, congratulated Trump for refusing to certify the agreement. He called Trump's speech a "courageous decision" and said the US president had created a chance to combat "Iran's aggression." Israel has repeatedly criticized the deal, saying it undermines regional stability and global security.

"The kingdom (of Saudi Arabia) and welcomes the firm strategy on Iran and its aggressive policy that was announced by US President Donald Trump," the official Saudi Press Agency said in a statement. Israel and Saudi Arabia have made statements similar to Trump's allegation that Iran is the "world's leading state sponsor of terrorism."

Continued support

Hours before Trump's announcement, several signatories warned Washington against taking a unilateral decision to withdraw from the accord. The German government said the Iran deal is an "important instrument" aimed at preventing Iran from acquiring a nuclear weapon, adding that Berlin will continue to support the agreement and its implementation.

Russian Foreign Minister Sergey Lavrov told his Iranian counterpart, Mohammad Javad Zarif, that Moscow would not back down from the deal, offering Moscow's "full commitment" to the agreement and its implementation.

China also offered its continued support for the deal, urging the international community to uphold its commitment laid out in the agreement. "We hope that the parties will continue to maintain and enforce the Iranian nuclear agreement," the Chinese Foreign Ministry said.

cmb, ls/sms (AP, AFP, dpa)