Democrats were quick to condemn Donald Trump’s decision to withdraw from the Iran nuclear, calling it a “grave mistake” and claiming his actions recklessly endangered the US’s relationships with its global allies.

Senator Bob Menendez, the top Democrat on the Senate foreign relations committee, said he believed Mr Trump’s decision to take the US out of the Joint Comprehensive Plan of Action (JCPOA) made it more likely, not less, that Iran would develop a nuclear weapon.

“With this decision President Trump is risking US national security, recklessly upending foundational partnerships with key US allies in Europe and gambling with Israel’s security,” he said.

“Today’s withdrawal from the JCPOA makes it more likely Iran will restart its nuclear weapons program in the future.”

As polls showed as many as one in three Americans believed the US should remain part of the deal, Mr Menendez also called on Mr Trump to immediately dispatch his national security team to Capitol Hill to explain his administration’s strategy toward Iran.

Chris Murphy, a Democrat on the Senate foreign relations committee, termed Mr Trump’s announcement as “terrible news”.

“Pulling out of the Iran deal is like a soccer player deliberately kicking the ball into their own team’s goal,” Mr Murphy said, according to the Associated Press. “There is nothing but downside for the US, especially since Trump has zero plan for what comes next.”

As Mr Trump said his Secretary of State Mike Pompeo, was on his way to North Korea to prepare for the president’s summit with Kim Jong-Un, Mr Murphy said the move would complicate such negotiations.

“It will make it even harder to convince Kim Jong-un to give up his nuclear weapons because we just showed that we can’t be trusted to live up to our end of a bargain,” he said.

Iranian president Hassan Rouhani: Donald Trump is 'not loyal to international commitments'

Democratic congressman Adam Schiff said the decision was an error of “historic proportions”.

“Scuttling an agreement that had halted the Iranian nuclear program and put in place an intrusive regimen of inspections without a credible Plan B is a mistake of historic proportions,” said Mr Schiff, the top Democrat on the House Intelligence Committee.

By contrast, Republicans were quick to defend Mr Trump’s decision, underscoring the party’s ongoing reluctance to challenge the president even as some had expressed reservations about pulling out of the accord.

Kevin McCarthy, the House majority leader, said Mr Trump was saying was staying true to what he promised as a candidate.

Iran protests – in pictures Show all 11 1 /11 Iran protests – in pictures Iran protests – in pictures University students at an anti-government protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures A university student at a protest inside Tehran University while a smoke grenade is thrown by anti-riot Iranian police, 30 December 2017 AP Iran protests – in pictures University students at a protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures University students run away from the police during an anti-government protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures An image grab taken from a handout video released by Iran's Mehr News agency reportedly shows a group of men pulling at a fence in a street in Tehran, 30 December 2017 AFP/Getty Iran protests – in pictures Demonstrators gather to protest in Tehran, 30 December 2017 AP Iran protests – in pictures Iranians chant slogans as they march in support of the government near the Imam Khomeini grand mosque in Tehran, 30 December 2017 AFP/Getty Iran protests – in pictures Iranians chant slogans as they march in support of the government near the Imam Khomeini grand mosque in Tehran, December 30 2017 Iran protests – in pictures Iranian clerics take part during a state-organized rally against anti-government protests in the country, in the holy city of Qom, south west Iran, 3 January 2018 EPA Iran protests – in pictures In this photo provided by the Iranian Students' News Agency, a clergyman takes a picture of a pro-government demonstration in the southwestern city of Ahvaz, Iran, 3 January 2018 ISNA via AP Iran protests – in pictures Pro-government demonstrators gather at the Massoumeh shrine in Iran's holy city of Qom, some 130 kilometres south of Tehran, 3 January 2018 AFP/Getty

“This is something the president campaigned on,” Mr McCarthy told Fox News. “I think President Trump understands foreign policy…If our main goal here is not to have Iran have a nuclear weapon, I would trust this president to actually get it done.”

Mr McCarthy said he had been briefed on the administration’s plans to exit the agreement, but as of now there had been no immediate demands from Congress to take action.

“I think it’s only appropriate that the world together becomes involved and gets a better agreement and makes sure Iran does not have a nuclear weapon,” he added.

The Republican Jewish Coalition, a group that aggressively lobbied against the Iran deal and is backed by the casino magnate Sheldon Adelson, welcomed Trump’s announcement.

“Today’s decision renewed hope for a truly long-term nuclear-free Iran,” the group said in a statement. “Iran continues to be an existential threat to Israel, and continues to menace Israel directly and through its proxies (such as Hezbollah).”

It added: “We appreciate President Trump’s bold foreign policy and look forward to his leadership in dealing with the Iranian threat.”