Iranian President Hassan Rouhani ruled out holding any bilateral talks with the United States. He also threatened to further cut Iran's commitments to a nuclear deal within days.
In an address to Parliament, Rouhani said any dialogue with the US would have to fall within the framework of the group of major powers that agreed to a landmark nuclear deal with Tehran in 2015.
He also said Iran was ready to further reduce its commitments to the accord in the coming days if current negotiations with European nations yield no results by
Thursday.
Tehran and Washington have been at loggerheads since May last year when President Donald Trump unilaterally withdrew from the nuclear deal and began reimposing crippling sanctions.
The arch-foes were on the cusp of confrontation in June when Iran downed a US drone and Trump ordered retaliatory strikes before cancelling them at the last minute.
The 2015 deal was agreed between Iran and permanent members of UN Security Council Britain, China, France, Russia and the United States plus Germany.