TEHRAN, Iran 

Iran has submitted its response to US comments on a European Union draft proposal aimed at salvaging the 2015 nuclear deal, calling it "constructive," but Washington has not reacted positively.

Iranian Foreign Ministry spokesman Nasser Kanaani in a statement early Friday said the response was sent to the EU coordinator, adding it has a "constructive approach" to finalize the negotiations

“After receiving the US response, the Islamic Republic’s expert team examined it carefully, and the response was compiled and submitted to the coordinator tonight,” Kanaani said.

He asserted that the response was put together “following evaluations at various levels.”

The US State Department confirmed receiving the response but did not assess it positively.

“We are studying it and will respond through the EU, but unfortunately it is not constructive,” said Deputy State Department spokesman Vedant Patel.

An unnamed Biden administration official was quoted as saying by Politico that based on Iran's response to the US comments, "we appear to be moving backwards."

Negotiations between Iran and the world powers to revive the 2015 nuclear accord have been underway in the Austrian capital Vienna since April last year, marked by multiple interruptions.

Josep Borrell, the EU foreign policy chief and coordinator of indirect talks between Iran and the US, proposed a new draft proposal after the latest round of talks in Vienna last month, which came after a five-month hiatus.

Iran filed its response to the EU draft proposal on Aug. 15, a week after the talks ended in Vienna. The Biden administration responded to Iran's comments through the EU coordinator on Aug. 24.

The two long-time adversaries have reportedly agreed to find a way around key sticking points, with Iran dropping its demand for the US to remove the Islamic Revolutionary Guard Corps (IRGC) from its Foreign Terrorist Organizations list.

French President Emmanuel Macron exuded confidence Thursday that a deal will be concluded "in the next few days.” France is one of the signatories to the original 2015 accord.

Iran's Foreign Minister Hossein Amirabdollahian in a phone call Thursday with his Emirati counterpart Sheikh Abdullah bin Zayed Al Nahyan said Tehran has "shown goodwill and seriousness" about reaching a "robust and lasting deal."

On Wednesday during a joint press conference with his Russian counterpart Sergey Lavrov in Moscow, the top Iranian diplomat stressed the importance of "stronger guarantees" from the US.

The details of Iran's response to US comments on the EU draft proposal are still unclear, but the negative response from Washington indicates that a deal in Vienna is still out of reach.