An advisor to Iran’s negotiating team has criticized Washington’s reaction to Tehran’s latest position on reviving the 2015 nuclear deal, saying for the US "constructive" means accepting its terms.

Mohammad Marandi, who acts as de facto spokesman for the Islamic Republic’s nuclear negotiating team, said in a tweet on Friday that “It's time for the Biden team to make a serious decision.”

Noting that If the United States makes “the right decision, an agreement can be swiftly concluded,” he said that “For the US 'constructive' usually means accepting US terms; for Iran it means a deal that is balanced and protected.”

Iran’s Foreign Ministry spokesperson Nasser Kanaani said early on Friday that Tehran has sent a "constructive" response to US proposals, but the US State Department gave a different assessment.

"We can confirm that we have received Iran's response through the EU," a White House National Security Council spokesperson Adrienne Watson said. "We are studying it and will respond through the EU, but unfortunately it is not constructive,” adding that "Some gaps have closed in recent weeks, but others remain."

Also on Friday, Tasnim news, affiliated with the Revolutionary Guard, quoted Ebrahim Azizi, the deputy chairman of the Iranian Parliament's National Security and Foreign Policy Committee, as saying that the US should decide whether it wants to finalize the agreement or not. “Iran's most important demand is economic benefit,” he said, reiterating that “the safeguard issues must be also resolved and all allegations about Iran's nuclear issue must be dropped.”