Iranian Foreign Ministry has claimed the Western side realised it must "back down" from its "maximal demands," as nuclear talks in Vienna are set to resume.
Iran said it has detected a new "realism" on the part of Western countries, ahead of further negotiations in Vienna aimed at rescuing an accord on its nuclear programme.
Speaking at a briefing in Tehran, ministry spokesperson Saeed Khatibzadeh said on Monday this round of discussions will be more "in-depth" towards reviving the 2015 nuclear deal with world powers.
"We sense a retreat, or rather realism from the Western parties in the Vienna negotiations, that there can be no demands beyond the nuclear accord," Khatibzadeh told reporters.
However, "it is too early to judge if the United States and the three European countries have drawn up a real agenda to commit to lifting sanctions," he said.
"Today is the time for the opposing parties to show their commitment and show that we can progress in the area of lifting sanctions, of guarantees and verification, on which we have made little progress," the spokesman said.
He also confirmed Iran has been exchanging views and proposals with the US unofficially and through the other negotiating parties.
US pursuing diplomacy
On Thursday, Washington voiced concern about a new Iranian space launch last week but indicated it was still pursuing diplomacy to return to a nuclear deal.
"The United States remains concerned with Iran's development of space launch vehicles, which pose a significant proliferation concern," a State Department spokesperson said.
"Iran's nuclear program was effectively constrained by the JCPOA," the spokesperson said.
"That is why we are seeking a mutual return to full compliance with the deal."
Trump's successor President Joe Biden backs a return to the nuclear deal, with Washington indirectly taking part in the European-brokered negotiations on reviving the so-called Joint Comprehensive Plan of Action (JCPOA).
Negotiations to restore the accord began last year but stopped in June as Iran elected ultraconservative President Ebrahim Raisi.
They resumed in late November and the latest round is due to restart on Monday after a three-day break for the end of year holidays.