Washington has been pressing Tehran to return to full compliance with the 2015 Joint Comprehensive Plan of Action, or JCPOA, which lifted economic sanctions on Iran in exchange for curbs on country's nuclear program.
U.S. President Donald Trump quit the deal in 2017. Two years later, Iran announced it had begun enriching uranium to levels proscribed by the JCPOA, alarming western nations that nuclear weapons could soon be within its reach.
"We are getting close to a point at which returning to compliance with the JCPOA will not in and of itself recapture the benefits of the JCPOA and that’s because Iran has been using this time to advance its nuclear program in a variety of ways," Blinken said.
Blinken made the remarks after a trilateral meeting with the foreign ministers of Israel and the United Arab Emirates.