United Nations Secretary General Antonio Guterres has urged United States President Donald Trump not to walk away from the Iran nuclear deal, BBC reported on Wednesday. Under the deal, Iran agreed to cut down on its uranium programmes so that international sanctions against it could be withdrawn.

Guterres told BBC that there was a real risk of war if the 2015 deal was not preserved. “If one day there is a better agreement to replace it, it’s fine, but we should not scrap it unless we have a good alternative.” Trump has till May 12 to decide whether to continue with the deal.

In October, Trump had refused to certify that Iran had been complying with the agreement, and had threatened to end the agreement. This has lead to diplomatic tensions with Iran as well as with US allies keen to preserve the agreement.

“I believe the JCPOA [the Iran nuclear deal] was an important diplomatic victory and I think it will be important to preserve it but I also believe there are areas in which it will be very important to have a meaningful dialogue because I see the region in a very dangerous position,” Guterres said, according to Reuters.

Iran’s ambassador to the United Kingdom Hamid Baeidinejad on Wednesday told CNN that there “would be no deal left” if the United States pulls out of the agreement.

Earlier this week, Israel had accused Iran of lying about its secret nuclear programme. President Benjamn Netanyahu said Israel had files to prove that Iran had a secret nuclear weapons programme, code-named ‘Project Amad’, until 2003.