The Iranian foreign ministry denied on Monday a claim by U.S. National Security Advisor Jake Sullivan that there were direct talks between the two countries over the past few months, official news agency IRNA reported.

"Since the beginning of the negotiations on the revival of the 2015 nuclear deal in Vienna, Iran has held no direct talks with the United States," said Saeed Khatibzadeh, the ministry's spokesman, in an address to a weekly press conference.

On Friday, Sullivan told reporters in Washington that the United States has "communicated both through the Europeans and directly to Iran."

"Iran has received some messages on the issues of negotiations in written and unwritten forms through EU mediators since the start of the talks in Vienna, to which answers were given on the spot," Khatibzadeh noted.

In May 2018, former U.S. President Donald Trump pulled Washington out of the Iranian nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), and reimposed unilateral sanctions against Tehran in a bid to hammer out a new deal.

Since early April this year, representatives from China, France, Germany, Russia, Britain and Iran have held seven rounds of negotiations in the Austrian capital, with the United States involved indirectly, aiming to bring the United States back to the JCPOA and prepare the ground for its full implementation.

The seventh and latest round of the talks started on November 29 and concluded on Friday.

"Today, we have two new agreed-upon texts, which are the results of the intense negotiations over the past few days in the Austrian capital," Khatibzadeh said.

"The new texts have incorporated Iran's views compared to the previous ones. We now have texts according to which we can continue the future talks," he added.

On the U.S. approach to the talks and its intention, the Iranian spokesman said Washington has offered "no tangible proposal or text" to other parties, placing "a big question mark on America's intention."