US Secretary of State Antony Blinken gives opening remarks as he meets with local labor leaders at the IBEW Local #5 in Pittsburgh, Pennsylvania, US September 30, 2021, Rebecca Droke/Pool via REUTERS

The United States was “absolutely in lock step” with Britain, Germany and France on getting Iran back into a nuclear deal, Secretary of State Antony Blinken said on Sunday, but he added it was unclear if Tehran was willing to rejoin the talks in a “meaningful way.”

Blinken’s remarks in an interview with CNN on Sunday come a day after the United States, Germany, France and Britain urged Iran to resume compliance with a 2015 nuclear deal in order to “avoid a dangerous escalation.”

The accord, under which Iran curtailed nuclear work seen as a risk of developing nuclear weapons in exchange for a lifting of global sanctions, unraveled in 2018 after then-President Donald Trump withdrew the United States, prompting Tehran to breach limits on uranium enrichment set by the pact.

“It really depends on whether Iran is serious about doing that,” Blinken said on Iran rejoining the nuclear talks. “All of our countries, working by the way with Russia and China, believe strongly that that would be the best path forward,” he added.

The nuclear deal is not the only point of contention between Iran and the United States. On Friday, the United States issued a fresh round of Iran-related sanctions tied to an Islamic Revolutionary Guard Corps drone program that it said threatened regional stability.

President Joe Biden said on Sunday that the United States will “respond” to actions Iran has taken against Washington’s interests, including drone strikes.

Leaders of the United States, Britain, France and Germany, hoping to persuade Tehran to stop enriching uranium to near-weapons-grade levels, said on Saturday they wanted a negotiated solution.

“But we do not yet know whether Iran is willing to come back to engage in a meaningful way,” Blinken said on Sunday. “But if it isn’t, if it won’t, then we are looking together at all of the options necessary to deal with this problem.”

Iran’s foreign minister said separately on Sunday that if the United States was serious about rejoining Tehran’s 2015 nuclear deal with world powers, Biden could just issue an “executive order,” the state-owned Iran newspaper reported.

“It is enough for Biden to issue an executive order tomorrow and they (US) announce they are rejoining the pact from the point where his predecessor left the deal,” Iranian Foreign Minister Hossein Amirabdollahian said. “If there is a serious will in Washington to return to the deal, there is no need for all these negotiations at all.”

Talks between Iran and world powers aimed at salvaging the deal, which started in April, are slated to resume at the end of November, the Islamic Republic’s top nuclear negotiator said on Wednesday.