UNITED NATIONS (AP) — A top Iranian official warned Wednesday that European threats to reimpose sanctions could lead Iran to withdraw from an international pact that limits the spread of nuclear weapons, one of the last remaining safeguards against the Islamic Republic’s nuclear program.

Iranian Deputy Foreign Minister Kazem Gharibabadi discussed with reporters his country’s recourse against further financial punishment ahead of a critical meeting Friday with Britain, France and Germany.

The talks between Iran and some of the remaining members of the 2015 nuclear deal, which the U.S. withdrew from in President Donald Trump’s first term, are expected to take place in Istanbul.

The three European countries have suggested triggering a so-called snapback provision in that accord that would reimpose sanctions on Iran if there is no progress on a deal to limit its nuclear program by August. The 2015 deal had eased economic penalties on Iran in exchange for restrictions and monitoring of its nuclear program, which Iran has insisted is peaceful.

Gharibabadi, who has been part of the nuclear negotiation team, said that despite domestic pressure to withdraw from the separate, older Nuclear Non-Proliferation Treaty, especially in the aftermath of the recent Israeli and U.S. strikes on its nuclear sites, Iran has remained compliant with the 1970 treaty.

“But, I’m quite confident that if the snapback is triggered, Iran will not show more restraint in this regard,” Gharibabadi said.

If Iran does exit the treaty, it will be just the second country to do so, after North Korea in 2003, whose withdrawal has never been formally accepted.

The warning from Iran comes as the Trump administration is once again seeking to reach a deal with Tehran on its nuclear program. The two sides had held several rounds of talks before Israel staged a surprise attack in June.

Gharibabadi and Iran’s foreign minister, Abbas Araghchi, have remained optimistic that the triggering of sanctions and withdrawal from the treaty can be avoided with “diplomacy and negotiation.”

Gharibabadi said Friday’s meeting is very important but that its success will depend on how the Europeans approach Iran this time around.

“We have always valued our meetings with the European countries. But there is an important issue: I think we have always told them that the policies of the European countries should be independent,” he said. “They should not coordinate their positions with the Americans.”

He added, “If this is the case, why should we negotiate with the Europeans when we can negotiate with the Americans?”

Iranian officials, including Gharibabadi, said they are open to proposals on how to prevent further sanctions and “prevent a more complicated situation.”