Iran will "immediately reverse" actions in respect of its nuclear programme when U.S. sanctions are lifted, its foreign minister said on Friday, reiterating Tehran's position on Washington's offer to revive talks.
The Joe Biden administration said on Thursday it was ready to revive a 2015 agreement between Iran and world powers that former president Donald Trump abandoned in 2018 before reimposing sanctions on Iran.
When sanctions are lifted, "we will then immediately reverse all remedial measures. Simple," Foreign Minister Mohammad Javad Zarif said on Twitter.
On Thursday, Zarif had tweeted that Iran's "remedial measures" were in response to violations of the accord by the U.S., Britain, France and Germany. Other signatories to the 2015 deal were China and Russia.
Earlier, Zarif said in an interview posted on a government site that the United States had not only failed to fulfil its obligations, but continues Trump's "failed maximum pressure" despite claiming it is ready to revive the nuclear agreement.
"Thus the Europeans must note that pressure on Iran does not work, nor are worthless remarks of any use," Zarif said, adding: "As soon as we see steps by the United States and Europe toward fulfilling their obligations, we will immediately react and return to our commitments."
Separately, Foreign Ministry spokesman Saeed Khatibzadeh said in a tweet on Friday: "US must act: lift sanctions. We will respond."
In London, UK junior foreign minister James Cleverly reiterated that Iran had to resume compliance with the deal, adding the West should not send signals that it is prepared to overlook Tehran's breaches of the accord.
Breaches of the deal by Iran began in 2019, about a year after Trump withdrew from it. U.S. Secretary of State Antony Blinken said on Thursday the Biden administration would return to the accord if Tehran came into full compliance with it.
Tehran has set a Feb. 23 deadline for Washington to begin reversing sanctions, otherwise, it says, it will take its biggest step yet to breach the deal - banning short-notice inspections by the U.N. nuclear watchdog, the International Atomic Energy Agency.
Britain, France, Germany, and the United States called on Iran to refrain from that step and repeated their concerns over recent actions by Tehran to produce uranium enriched up to 20% and uranium metal.
Biden has insisted he will not remove Trump's sanctions until Iran returns to compliance -- but the administration Thursday undid two symbolic steps by the last administration.
In a letter to the United Nations, the United States said it no longer believed that the world body had "snapped back" sanctions on Iran.
Blinken's predecessor Mike Pompeo last year argued the United States was still a "participant" in the Security Council resolution that blessed the nuclear deal -- despite withdrawing later -- and therefore could reimpose sanctions.
The argument had been dismissed by the United Nations and close US allies at the time.
In his tweet, Zarif said Iran agreed with the Biden administration's decision.
"US acknowledged Pompeo's claims" regarding UN Security Council Resolution 2231 "had no legal validity. We agree," Iran's top diplomat wrote.
The Biden administration also reversed draconian curbs on Iranian diplomats in New York who were barred from all but a few blocks around the United Nations and their mission.
Under the terms of a bill adopted by its conservative-dominated parliament in December, Iran will restrict some inspections by the International Atomic Energy Agency if the United States does not lift its sanctions imposed since 2018 by Sunday.
IAEA chief Rafael Grossi is to travel to Tehran on Saturday for talks with the Iranian authorities to find a solution.
A joint statement by the four foreign ministers after the virtual meeting convened by France urged "Iran to consider the consequences of such grave action, particularly at this time of renewed diplomatic opportunity."
The United States and Iran have had no diplomatic relations for four decades but they began frequent contact to negotiate the 2015 nuclear deal.
The nuclear accord was adamantly opposed by Iran's regional rivals Israel and Saudi Arabia, which both enjoyed tight partnerships with Trump.
While Iran's policy is ultimately determined by supreme leader Ayatollah Ali Khamenei, Iranian presidential elections in June add another time pressure factor.
Rouhani -- a key advocate of nuclear diplomacy with global powers -- is set to step down after serving the maximum two consecutive terms, and a more hardline figure is likely to replace him.
