British Prime Minister Theresa May, French President Emmanuel Macron and German Chancellor Angela Merkel said they "stand committed to its full implementation by all sides," according to a joint statement released by May's Downing Street office.
They said they "take note of President Trump's decision" not to recertify Iran's compliance with the Joint Comprehensive Plan of Action (JCPOA) to the US Congress and were "concerned by the possible implications."
"The nuclear deal was the culmination of 13 years of diplomacy and was a major step towards ensuring that Iran's nuclear program is not diverted for military purposes," They added.
"We encourage the US Administration and Congress to consider the implications to the security of the US and its allies before taking any steps that might undermine the JCPOA, such as re-imposing sanctions on Iran lifted under the agreement."
"Our governments are committed to ensuring the JCPOA is maintained," they stressed, AFP reported.
Despite Iran’s stress on peaceful nature of its defensive capabilities including the ballistic missile program, the three leaders said they were concerned about Iran's ballistic missile program and that they "stand ready to take further appropriate measures to address these issues."
The US president has violated its obligations enshrined in the nuclear deal. In a White House speech on Friday, Trump stopped short of withdrawing from the 2015 accord, but "decertified" his support for the agreement and left its fate in the hands of Congress.