Uranium enrichment has been a key point of contention in five rounds of talks since April to ink a new accord that would replace the deal abandoned by US President Donald Trump during his first term in 2018.

"Under our potential Agreement - WE WILL NOT ALLOW ANY ENRICHMENT OF URANIUM!" Trump said on his Truth Social network on Monday.

Asked about Trump's comments, Kremlin spokesman Dmitry Peskov said: "Countries have the right to peaceful energy, the use of peaceful atomic energy must take place exclusively under the strict control of the International Atomic Energy Agency."

"We believe that countries should keep this right," he added.

Allies Iran and Russia have deepened military ties amid Moscow's offensive on Ukraine.

Peskov also repeated Moscow's support for talks "aimed at a peaceful resolution" of the standoff between Iran and the United States.