The United States offered "very serious" ideas to Iran on how to revive a nuclear deal during talks in Vienna but is waiting for Iran to show the same "seriousness," a US official said Friday.
"The United States team put forward a very serious idea and demonstrated a seriousness of purpose on coming back into compliance if Iran comes back into compliance," the official told reporters as talks broke for the weekend.
But the official said the United States was waiting for its efforts to be "reciprocated" by Iran.
"We saw some signs of it but certainly not enough. There's still question marks about whether Iran has the willingness to... take the pragmatic approach that the United States has taken to come back into compliance with its obligations under the deal," he said.
President Joe Biden supports a return to the 2015 agreement trashed by his predecessor Donald Trump under which Iran drastically scaled back nuclear work in return for promises of sanctions relief.
Iran has demanded that the United States first lift all sanctions imposed by Trump before it rolls back moves out of nuclear compliance that it had taken in protest.