Donald Trump and Theresa May
Donald Trump and Theresa May Reuters

British Prime Minister Theresa May on Tuesday spoke to U.S. President Donald Trump and urged him not to end the Iran nuclear deal, arguing it is "vitally important for regional security".

The Prime Minister called Trump after it was announced he will deliver his decision on his "overall Iran strategy" later this week, according to The Telegraph.

A Downing Street spokesman said May "reaffirmed the UK's strong commitment to the deal alongside our European partners, saying it was vitally important for regional security" during the conversation with Trump.

"The PM stressed that it was important that the deal was carefully monitored and properly enforced," the spokesman added.

Trump has a deadline of October 15 to recertify the nuclear deal signed in 2015 between Iran and world powers.

U.S. officials say he intends to tell Congress next week that Tehran is not honoring its side of the bargain, paving the way for new sanctions on the Islamic Republic.

On Monday, Russia warned would be "negative consequences" if Trump fails to uphold the Iran nuclear deal.

"Obviously if one country leaves the deal, especially such a key country as the U.S., then that will have negative consequences," said President Vladimir Putin's spokesman, Dmitry Peskov.

"We can only try to predict the nature of these consequences, which we are doing now," he told journalists.

May's conversation with Trump comes a day after she spoke with Prime Minister Binyamin Netanyahu, saying that the nuclear deal with Iran is important and must be preserved because it has "neutralized" the possibility of the Iranians acquiring nuclear weapons for more than a decade.

May said the UK remains firmly committed to the deal and that it believes the deal is vitally important for regional security. She said it was important that the deal is carefully monitored and properly enforced, and that both sides deliver on their commitments.