U.S. Secretary of State Anthony Blinken said he discussed Iran issues with Russian Foreign Minister Sergei Lavrov on Friday, warning that there is only a small window to successfully complete negotiations to save the 2015 Iran nuclear deal, Reuters reported.

Blinken told reporters that the deal is an example of how Moscow and Washington can work together on security issues, urging Russia to use its influence and relationship with Iran to instill a sense of urgency in Tehran.

Blinken said there was still a window to return to the deal but warned that Tehran's continuing nuclear advances would hinder any return to the accord if a fresh pact was not reached in coming weeks.

"The talks with Iran about a mutual return to compliance with the JCPOA (2015 deal) have reached a decisive moment," Blinken said.

"If a deal is not reached in the next few weeks, Iran's ongoing nuclear advances will make it impossible to return to the JCPOA. But right now, there's still a window, a brief one, to bring those talks to a successful conclusion and address the remaining concerns of all sides," he concluded.