WASHINGTON – US President Donald Trump warned on Monday that Iran is "playing with fire" after Tehran said it exceeded a limit on enriched uranium reserves under a 2015 nuclear deal abandoned by Washington.

Israel urged European states to sanction Iran, while Russia voiced regret but said the move was a consequence of US pressure, which has pushed the deal towards collapse.

Britain called on Tehran "to avoid any further steps away" from the landmark deal, and the UN said Iran must stick to its commitments under the accord.

"Iran has crossed the 300-kilogram limit based on its plan" announced in May, Foreign Minister Mohammad Javad Zarif told semi-official news agency ISNA.

But he also said the move could be reversed.

"They know what they're doing. They know what they're playing with and I think they're playing with fire," Trump told reporters at the White House when asked about Iran.

The United States withdrew from the nuclear deal last year and hit Iran's crucial oil exports and financial transactions as well as other sectors with biting sanctions.

Tehran, which has sought to pressure the remaining parties to save the deal, announced on May 8 it would no longer respect the limit set on its enriched uranium and heavy water stockpiles.

It threatened to abandon further nuclear commitments unless the remaining partners -- Britain, China, France, Germany and Russia -- helped it circumvent sanctions, especially to sell its oil.

The White House had earlier said that "the United States and its allies will never allow Iran to develop nuclear weapons," vowing to continue exerting "maximum pressure" on the regime.

"It was a mistake under the Iran nuclear deal to allow Iran to enrich uranium at any level," spokeswoman Stephanie Grisham said in a statement. – AFP