Iran welcomes France's efforts to save the 2015 nuclear deal, the Iranian Foreign Ministry spokesman said on Wednesday as French President Emmanuel Macron's top diplomatic adviser visited Tehran for talks to help ease the crisis.

Iran threatened on Monday to restart deactivated centrifuges and ramp up enrichment of uranium to 20 percent purity in a move away from the nuclear accord.

Tehran has been pushing the European signatories to the accord to protect Iran from U.S. sanctions, which Washington reimposed after leaving the pact last year.

Iran's state news agency IRNA reported that Foreign Ministry spokesman Abbas Mousavi "welcomed France's role in reducing tension and implementing the accord."

"The French are part of efforts ... to keep the nuclear deal alive," Mousavi was quoted as saying during the visit by Emmanuel Bonne, Macron's top diplomatic adviser.

On Monday, Iran surpassed the 3.67 percent uranium enrichment limit set under the 2015 deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), signed between China, the U.S., Russia and EU countries Britain, France and Germany.

Under the pact, most international sanctions against Tehran were lifted in return for limitations on its nuclear work. But U.S. President Donald Trump last year withdrew from the deal and reimposed sanctions.

France and Iran have agreed to seek conditions to resume nuclear talks. "The President of the Republic has agreed with his Iranian counterpart to explore by July 15 conditions to resume dialogue between the parties," according to a statement released by Macron's office last Saturday.

The statement added Macron will keep on talking with Iranian authorities and other involved parties to "engage in a de-escalation of tensions related to Iranian nuclear issue."

"The president recalled his deep concern in the face of the risk of a new weakening of the 2015 nuclear accord, and the consequences that would necessarily follow," said the statement.

Trump and Macron on Monday discussed "ongoing efforts to ensure that Iran does not obtain a nuclear weapon" and Iran's "destabilizing behavior" in the Middle East.

U.S. Vice President Mike Pence said on Monday that his country will continue to put economic pressure on Iran and defend U.S. interests after Tehran breached the 2015 nuclear deal.

"Let me be clear: Iran should not confuse American restraint with a lack of American resolve," said Pence, adding "we hope for the best, but the United States of America and our military are prepared to protect our interests and protect our personnel and our citizens in the region."

China expressed regret over Iran's decision to breach the 2015 nuclear deal. "We call on all relevant sides to exercise restraint and step up dialogue through the mechanism of the UN committee to seek conditions for a resumption of dialogue and de-escalation of tensions," Geng Shuang, a spokesperson for Chinese Foreign Ministry, said Monday.

The spokesperson also condemned the U.S. for being the root cause of the tense situation with its failed "maximum pressure" strategy.

"By unilaterally pulling out of the JCPOA and exercising its 'long-arm jurisdiction' to impose sanctions on Iran, the U.S. has posed major hindrances for Iran and other involved parties to keep fulfilling their commitment to the pact," he said, adding that the current situation has proven that unilateral bullying by the U.S. will create more and greater crises on a global scale.

"We continue to urge Iran not take further measures that undermine the nuclear deal to stop and to reverse all activities that are inconsistent with the JCPOA, including the production of low-enriched uranium, " an EU spokeswoman told reporters.

(Cover: Abbas Mousavi, spokesman for Iran's Foreign Ministry, gives a press conference in the capital Tehran on May 28, 2019. /VCG Photo)

(With input from agencies)