Iran will react to any reimposition of UN sanctions on its nuclear energy program, an Iranian Foreign Ministry spokesman said today, without specifying what actions Tehran might take.

A French diplomatic source told Reuters last week that European powers would be forced to reinstate U.N. sanctions on Iran under the so-called “snapback mechanism” if there is no agreement that guarantees European security interests.

The “snapback mechanism” is a process that provides for the reimposition of UN sanctions on Tehran under the 2015 nuclear deal that lifted the measures in exchange for restrictions on Iran’s nuclear program.

“The threat to use the snapback mechanism lacks legal and political basis and will receive an appropriate and proportionate response from the Islamic Republic of Iran,” Foreign Ministry spokesman Esmail Bagaei told a news conference, without giving further details.

The 2015 agreement with Britain, Germany, France, Germany, France, the US, Russia and China – known as the Joint Comprehensive Plan of Action (JCPOA) – states that if the parties cannot resolve complaints of “significant failure” by Iran (i.e. to meet its obligations under the agreement), the “snapback mechanism” process can be triggered by the 15-member UN Security Council.

“The European parties, which are constantly trying to use this possibility as a tool, have themselves committed serious and fundamental violations of their obligations under the CSTO,” Bagaei said. “They have failed to fulfil their obligations under the CSTO, so they have no legal or moral basis to resort to this mechanism.”

Western countries accuse Iran of planning to build a nuclear weapon, which Tehran denies.

The United States withdrew from the deal in 2018, during the first presidential term of Donald Trump, who called the agreement “weak.”

Trump, whose second presidential term began in January, has called on Tehran to return to talks on a new deal after reaching a ceasefire last month that ended a 12-day war between Iran and Israel that destabilized the Middle East.

Responding to a question on whether Iranian Foreign Minister Abbas Araghchi would meet with Trump’s special envoy for the Middle East, Steve Whitcoff, Bagaei said no date or venue had been set for the resumption of negotiations between the US and Iran over Tehran’s nuclear program.