US President Donald Trump yesterday told French President Emmanuel Macron that the United States was going to pull out of the international nuclear agreement with Iran, the New York Times reported, citing a person briefed on the conversation.

The source said the United States is preparing to reinstate all sanctions it had waived as part of the deal and impose additional economic penalties, the Times reported.

Trump is to make an announcement on the Iran deal at 2:00pm (1800 GMT).

One senior European official closely involved in Iran diplomacy told Reuters that US officials had indicated late on Monday that Trump would withdraw from the agreement but it remained unclear on what terms and whether sanctions would be reimposed.

The 2015 deal, the signature foreign policy achievement of Trump's predecessor Barack Obama, eased sanctions on Iran in exchange for Tehran limiting its nuclear program to prevent it from being able to make an atomic bomb.

Earlier, one senior European official closely involved in Iran diplomacy said US officials had indicated late on Monday that Trump would withdraw from the deal but it remained unclear on what terms, and whether sanctions would be reimposed.

A senior Western diplomat said France, Britain and Germany - which were also party to the agreement - were working on the assumption of a hard US exit after a call last week between US Secretary of State Mike Pompeo and European officials at which he made clear talks on rescuing the deal would not go further.

"He let it be known that it was over," the diplomat said.

European officials understood this to mean that Trump would not renew sanctions waivers, a move which would in effect kill the deal.

Trump planned to discuss his decision in a phone call on Tuesday with French President Emmanuel Macron, a senior White House official said.

Trump has consistently threatened to pull out of the 2015 agreement because it does not address Iran's ballistic missile program or its role in wars in Syria and Yemen, and does not permanently prevent Tehran from developing nuclear weapons.

European leaders have warned that a US withdrawal would undo years of work that has kept nuclear weapons out of Iran's hands.

In Washington, the Republican chairman of the US House of Representatives Foreign Affairs Committee said the United States should continue to fix flaws in accord and "enforce the hell" out of it, but not withdraw.

Speaking hours before Trump was due to announce his decision, Ed Royce said tearing up the deal would not recover cash sent to Iran's government or "galvanize" allies into addressing Iran's dangerous activities.

"I fear a withdrawal would actually set back those efforts," he said in a statement.

A senior French official doubted Trump had taken heed of European concerns.