Congressman Darrell Issa's office confirmed to Sputnik that US officials in a closed briefing told lawmakers that it appears negotiations are at a standstill.
"I can confirm these comments," Issa's office said when asked about the report.
US Secretary of State Antony Blinken claimed earlier this week that he does not expect restoration of the Iran nuclear deal in the near future.
He also claimed that Iran continues to try to add issues to the negotiations that the United States cannot agree to.
Tehran says Iran's case in the International Atomic Energy Agency should be closed so that it is not misused as a pressure lever in JCPOA talks.
The United States, under former president Donald Trump, abandoned the agreement in May 2018 and reinstated unilateral sanctions that the agreement had lifted.
The talks to salvage the agreement kicked off in the Austrian capital city of Vienna in April last year, months after Joe Biden succeeded Trump, with the intention of examining Washington's seriousness in rejoining the deal and removing anti-Iran sanctions.
Despite notable progress, the US indecisiveness and procrastination caused multiple interruptions in the marathon talks. Four days of intense talks between representatives of Iran and the five remaining parties to the JCPOA ended on August 8 with a modified text proposed by the EU on the table.
Iran submitted its response to the EU draft proposal on August 15, a week after the latest round of talks wrapped up which the bloc described as “reasonable". After submitting its response, Tehran urged Washington to show "realism and flexibility" in order to reach an agreement.
RHM/PR