In March, he sent a letter to Iran’s supreme leader Ayatollah Ali Khamenei urging talks and warning of possible military action if Iran refused.
On Thursday, the New York Times reported that Trump had blocked an Israeli plan to strike Iranian nuclear facilities in favour of seeking a negotiated deal.
On Tuesday, Khamenei cautioned that while the talks with the US had started well, they could yet prove fruitless.
“The negotiations may or may not yield results,” he said.
On Wednesday, Araghchi said Iran’s enrichment of uranium was not up for discussion after Witkoff called for a halt.
Witkoff had previously demanded only that Iran return to the 3.67 percent enrichment ceiling set by the 2015 deal.
Araghchi said he hoped to start negotiations on the framework of a possible agreement, but that this required “constructive positions” from the US.
“If we continue to (hear) contradictory and conflicting positions, we are going to have problems,” he warned.
On Thursday, Iran’s top diplomat headed to Moscow on a “pre-planned” visit to the Tehran ally.
The Kremlin said that Russia stood ready to do “everything” in its power to help resolve the standoff over Iran’s nuclear programme.
