WASHINGTON - US President Donald Trump on Tuesday spoke by phone with British Prime Minister Theresa May to address ways to block all means for Iran to acquire a nuclear weapon, according to the White House.

"President Trump underscored the need to work together to hold the Iranian regime accountable for its malign and destabilizing activities, especially its sponsorship of terrorism and its development of threatening missiles," said the White House in a statement.

Trump was expected to announce later this week an overall Iran strategy, including whether his administration will decertify Iran's compliance with the landmark Iran nuclear deal reached in 2015.

Multiple media reports had said Trump was expected to decertify Iran's compliance, a move that could lead to the potential collapse of the agreement, which was reached between Iran and the six world powers of Britain, China, France, Russia and the United States plus Germany in July 2015.

The deal, officially known as the Joint Comprehensive Plan of Action, has helped defuse Iran's nuclear crisis and bolstered the international non-proliferation regime.

Trump has long criticized the Iranian nuclear pact. In his speech delivered at the United Nations (UN) General Assembly last month, Trump called the agreement "an embarrassment" for the United States.

The Trump administration is due to inform the Congress by Oct 15 whether Tehran is complying with the deal. If it decides Tehran is not, it could open the way for US lawmakers to reimpose sanctions against Iran.

Last month, the International Atomic Energy Agency, a UN nuclear watchdog, said that Iran was playing by the rules set out in the nuclear accord.