(presstv) -- Trump has described the 2015 agreement, known as the Joint Comprehensive Plan of Action (JCPOA), negotiated under the Obama administration, as a giveaway to Iran and “one of the worst” deals ever, and has said it should be renegotiated or disbanded.

In the letter, the scientists said the lawmakers must ensure that the US remains committed to the agreement. They say renegotiating the deal is an unrealistic objective.

The letter also outlined certain strategies that could address US complaints regarding the landmark nuclear accord. The signatories include a designer of the hydrogen bomb and all three winners of this year’s Nobel Prize in physics.

Earlier this month, the US president refused to recertify Iran’s compliance to the agreement, leaving Congress to determine the fate of the JCPOA. Iran and European leaders have repeatedly rejected the possibility of negotiating a new deal.

Iran and the five permanent members of the United Nations Security Council – the United States, France, Britain, Russia and China – plus Germany signed the nuclear agreement on July 14, 2015 and started implementing it on January 16, 2016.

Under the JCPOA, Iran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions imposed against Tehran.

The US Congress now has less than 60 days to decide whether to reimpose economic sanctions on Tehran, lifted under the nuclear accord.

The other parties to the accord -- Britain, Germany, France, Russia, and China -- have all reaffirmed their commitment to the deal and urged the United States not to back out.

(File Photo: Iran’s nuclear power plant in Bushehr, southern Iran. by EPA)