In an open letter published in several newspapers on Thursday, the French, German and British lawmakers asked their US counterparts to persuade Trump not to abandon the deal, officially called the Joint Comprehensive Plan of Action (JCPOA).
"The US government threatens to abandon the JCPOA, although Iran fulfills its obligations under the agreement,” the letter read.
It also warned that "an exit from the US would have fatal consequences" and spell "lasting damage to our credibility as international partners in negotiation, and more generally, to diplomacy as a tool to achieve peace and ensure security."Presstv reported.
The European MPs further described the nuclear pact as a "major diplomatic breakthrough" and stressed that a US withdrawal "could provide a new source of devastating conflict in the Middle East and beyond.”
Similarly last month, a bipartisan group of over 100 US national security veterans explained why keeping the agreement alive is in the best interests of Washington.
Trump has been a vociferous critic of the Iran nuclear deal which was signed between Tehran and six world powers in 2015. He has called the JCPOA the “worst deal ever” and even threatened to tear it up.
In January, he decided to stick with the JCPOA, but gave the European signatories a May 12 deadline to "fix the terrible flaws" of the accord or have him abandon the agreement.
Iran maintains that it will not renegotiate the deal, an international document endorsed by the Security Council Resolution 2231.
Other parties to the agreement, namely Russia, China, Britain, Germany and France, have all criticized Trump’s hostile views, saying the deal is sound and has proven to be functioning.
The International Atomic Energy Agency (IAEA), which is tasked with monitoring Iran’s nuclear activities, has repeatedly verified Tehran's full commitment to its side of the bargain.