Russia says it sees no room for amendments or additions to the 2015 nuclear deal between Iran and six world countries.

“We are seriously concerned by all of this - I am referring to comments made by the presidents of the United States and France about the Joint Comprehensive Plan of Action (JCPOA) on the Iran nuclear program. Russia has repeatedly said that there is no possibility for some kind of revote for this document, changing or enlarging it,” the spokeswoman for the Russian Foreign Ministry Maria Zakharova said on Thursday.

Elsewhere in her remarks, Zakharova announced an unscheduled meeting of the foreign ministers of Russia, Iran and Turkey in Moscow on April 28, saying the three states – which are cooperating in a peace process on Syria – will exchange views on “including the worsening situation around the implementation of the JCPOA,” among other issues.

The US president has called the JCPOA the “worst deal ever” and threatened to pull Washington out of the accord, which has the firm support of the entire global community.

The accord lifted Iran’s nuclear-related sanctions in exchange for Tehran limiting certain aspects of its nuclear program.

In January, Trump ramped up pressure on the European parties to the deal to fix what he claimed to be the “flaws” in the accord by May 12 or he would no more extend the sanctions relief for Iran; a US obligation under the JCPOA.

Iran has repeatedly made it clear that the nuclear accord is not up for renegotiation, warning that Tehran would also withdraw from the accord if Washington does so.