The United States and France yesterday warned Iran that time was running out to return to a nuclear deal, voicing fear that Tehran's sensitive atomic activities could advance if talks drag on.
On the first high-level visit to Paris by President Joe Biden's administration, Secretary of State Antony Blinken and his French hosts saluted a new spirit of cooperation after four years of turbulence under Donald Trump.
But the two sides said that one key Biden promise -- to return to the 2015 accord on the Iranian nuclear programme that was trashed by Trump -- was at risk if the clerical regime does not make concessions during talks that have been going on for months in Vienna.
Blinken warned that the United States still had "serious differences" with Iran, which has kept negotiating since last week's presidential election won by hardliner Ebrahim Raisi.
"There will come a point, yes, where it will be very hard to return back to the standards set by the JCPOA," Blinken told reporters, using the formal name of the accord.
"We haven't reached that point -- I can't put a date on it -- but it's something that we're conscious of."
Blinken warned that if Iran "continues to spin ever more sophisticated centrifuges" and steps up uranium enrichment, it will bring nearer the "breakout" time at which it will be dangerously close to the ability to develop a nuclear bomb.
But Blinken said that Biden still supported a return to the accord, under which Iran had drastically scaled back its nuclear work until Trump withdrew in 2018 and imposed crippling sanctions.
France -- which like Britain, Germany, Russia and China had stayed in the 2015 accord despite pressure from Trump -- also ramped up pressure on Iran to move ahead.
Talks have stalled in part over Iran's insistence on the lifting of all sanctions, pointing to the promises of economic relief under the accord.
Meanwhile, in Washington, President Joe Biden and Afghan President Ashraf Ghani and Ghani's former political opponent, Abdullah Abdullah were set to meet.
"We are looking very carefully at the security on the ground in Afghanistan and we're also looking very hard at whether the Taliban is, at all, serious about a peaceful resolution of the conflict," Blinken told a joint news conference with France's foreign minister.