BERLIN (Reuters) - Iran told a German envoy seeking to preserve the 2015 nuclear deal that its patience was over and urged the treaty’s remaining signatories to fulfill their commitments after the United States pulled out, the Fars news agency reported on Thursday.

FILE PHOTO: Iranian Deputy Foreign Minister Abbas Araghchi pictured in Vienna, February 24, 2015. REUTERS/Heinz-Peter Bader/File Photo

Jens Ploetner, a political director in the German Foreign Ministry, met Iranian Deputy Foreing Minister Abbas Araghchi. A German diplomatic source told Reuters that talks with other Iranian official were also planned.

The semi-official Fars news agency said Araghchi had relayed Iran’s impatience during the talks.

Britain, France and Germany, which signed the 2015 deal along with the United States, China and Russia, are determined to show they can compensate for last year’s U.S. withdrawal from the deal, protect trade and still dissuade Tehran from quitting an accord designed to prevent it developing a nuclear bomb.

But Iran’s decision earlier this month to backtrack from some commitments in response to U.S. measures to cripple its economy threatens to unravel the deal, under which Tehran agreed to curbs on its uranium enrichment program in exchange for the removal of most international sanctions.

“At the center of the political director’s visit is the preservation of the Vienna nuclear accord (JCPOA),” the German diplomatic source told Reuters.

“After Iran’s announcement to partly suspend its commitments under the JCPOA, there is a window of opportunity for diplomacy to persuade Iran to continue to fully comply with the JCPOA.”

Ploetner knows Araghchi from the negotiations to clinch the JCPOA (Joint Comprehensive Plan of Action).

Tensions have soared between Iran and the United States since Washington sent more military forces to the Middle East, including an aircraft carrier, B-52 bombers and Patriot missiles, in a show of force against what U.S. officials say are Iranian threats to its troops and interests in the region.

On Wednesday, U.S. officials said the Defense Department was considering a U.S. military request to send about 5,000 additional troops to the Middle East.

Despite such pressure, Keyvan Khosravi, a spokesman for Iran’s Supreme National Security Council reiterated on Thursday that there would be no negotiations with Washington.

He said officials from several countries had visited Iran recently, “mostly representing the United States”, but that Tehran’s message to them was firm.

“Without exception, the message of the power and resistance of the Iranian nation was conveyed to them,” he said.

Fars earlier quoted a senior commander of the powerful Revolutionary Guards as saying the U.S.-Iranian standoff was a “clash of wills” and any enemy “adventurism” would meet a crushing response.

The German diplomatic source added: “The situation in the Persian Gulf and the region, and the situation around the Vienna nuclear accord is extremely serious. There is a real risk of escalation...In this situation, dialogue is very important.”