Former foreign ministers from a diverse group of countries have asked the U.S. Congress to uphold the nuclear deal with Iran known as JCPOA.

In an open letter addressed to congressional leaders published on Wednesday, they said that it was now upon Congress to keep the U.S. compliant with the the agreement. “We urge you to uphold the agreement, and not to take any unilateral action that seeks to expand, alter or renegotiate the terms of the JCPOA,” the letter reads.

The letter has been signed by 25 former top diplomats from various countries, including former Secretary of State Madeleine Albright, Joshka Fischer of Germany, Hubert Védrine of France, Malcolm Rifkind of UK, and Shlomo Ben-Ami of Israel who had met as part of Aspen Ministers Forum.

The writers pointed to President Donald Trump’s refusal to re-certify the agreement and reminded that senior U.S. national security officials have affirmed that Iran is meeting its commitments.

They said this conclusion is also shared by the members of 5+1 group – Britain, China, France, Germany, the European Union, and Russia, and the International Atomic Energy Agency which is in charge of monitoring and verifying Tehran’s compliance with the JCPOA.

The letter warned the United States about unilateral withdrawal from the agreement and said it would have “far-reaching adverse consequences for the security of the United States and America’s standing in the world.”

Such action may result in the emergence of a nuclear-armed Iran in the absence of a consensus among international community to impose previous sanctions on the country.

A possible U.S. withdrawal would also undermine its credibility and reliability in the future they wrote and would “make it virtually impossible to reach any diplomatic agreement with North Korea, whose nuclear weapons program is a pressing international threat.”

The writers of the letter said that they were troubled by Iran’s “destabilizing actions” in the region, including support for terrorism, however, those actions were not part of the nuclear agreement.

The Aspen Ministers Forum, a project of the Aspen Strategy Group, is an initiative of former foreign ministers from around the world and across the political spectrum.

The group says it seeks to develop concrete, non-partisan recommendations to address common global challenges, including the fight against terrorism, Middle East peace, humanitarian intervention, and reform of the international architecture.