The head of the judiciary is considered to be most likely to become Iran's next president in elections next month.
"There's still a fair distance to travel to close the remaining gaps," Biden's national security adviser Jake Sullivan said Sunday.
Ayatollah Ali Khamenei said the U.S. has "broken" its "promises tens of times, and it is the same now."
Sen. Jim Inhofe is leading a call for the Biden administration to "reset" its approach to nuclear negotiations with Tehran.
"I called on France to ... cease abiding by illegal sanctions imposed by the US," tweeted Iran Foreign Minister Javad Zarif, in follow-up remarks Saturday afternoon.
International Atomic Energy Agency chief Rafael Grossi told Newsweek on Tuesday that Iran must answer questions about uranium found at two alleged secret nuclear sites.
After the election in June, the White House will likely face more fractious negotiations with a hardliner president
The parliament in Tehran ordered an expansion of nuclear activities last year, setting off alarm bells in Washington, D.C.
Iran, bereft of wealthy allies and grappling with U.S. sanctions, sees the two nations as useful counterweights to Washington, D.C.
Iran's military officials are maintaining harsh rhetoric towards the U.S. despite Tehran's hope of reviving the JCPOA nuclear deal.
Both Tehran and Washington, D.C., have warned that the window for a deal to revive the JCPOA is closing.
With the ageing Ayatollah Ali Khamanei looking to secure the future of the regime, members of the Islamic Revolutionary Guard Corps are eyeing the presidency.
Iran has long offered a full prisoner exchange as a step towards a diplomatic thaw, and potential revival of the JCPOA nuclear deal.
Tit-for-tat attacks in Iraq and Syria risk undermining Biden's efforts to revive the nuclear deal with Tehran.
Israeli leaders remain staunchly opposed to the JCPOA nuclear deal and have threatened military action against Iran's nuclear program.
Defense Minister Benny Gantz said on Thursday that Israel will "stand independently" against Iran if needed.
Pentagon spokesperson John Kirby has come under fire for referring to Iran-aligned fighters as "Shia-backed militias."
The European JCPOA signatories withdrew a planned IAEA censure of Iran on Thursday, after Tehran threatened a "serious response."
Iran and the U.S. remain stuck in a stalemate over which side will take the first step to revive the JCPOA nuclear deal.
Israel has accused Iran of a fresh attack on commercial shipping in the Gulf of Oman as the U.S. and Iran remain in a nuclear stalemate.
Netanyahu has long led foreign opposition to the Iran nuclear deal, and was a major influence on President Donald Trump's decision to withdraw from the accord in 2018.
Iran's conservative-dominated parliament has made a legal complaint against Rouhani's government for agreeing a last-minute deal to secure international nuclear inspections.
Officials have agreed to maintain access for atomic energy inspectors, but Iran's standoff with the U.S. president over the nuclear deal continues.
The Biden administration said on Thursday it was ready to meet with JCPOA signatories and rescinded the previous administration's bid to reimpose United Nations sanctions on Tehran.
The Biden administration said on Thursday it was ready to meet with signatories of the JCPOA nuclear deal and discuss its revival.
The JCPOA European signatories could serve as a referee for a simultaneous U.S. and Iranian return to the nuclear deal.
One civilian contractor was killed and several Americans wounded in Tuesday's rocket attack in Iraq, which was claimed by an Iran-linked militia.
The former president still believed he could make a deal with Tehran even as relations collapsed during his term.
Exiled Iranian crown prince, Pahlavi, told Newsweek the historic normalization deals represent the "best prospect for peace and a meteoric rise in prosperity in the Middle East."