MOSCOW - Russia considers any discussion of regime change in Iran completely unacceptable, Kremlin spokesman Dmitry Peskov has said.

"This is unimaginable. Of course, it should be unacceptable even to talk about it openly," Peskov told British news outlet Sky News in response to Western rhetoric about potential power changes in Tehran.

He warned that any US involvement in a direct conflict between Israel and Iran will significantly escalate the situation and further destabilize the region.

"The situation is already extremely tense and poses dangers not only to the region but to global stability. Expanding the geography of the conflict and increasing the number of participants would be even more dangerous," he said.

Peskov further cautioned that US interference in the Israel-Iran conflict could "open Pandora's box".

His remarks followed reports that US President Donald Trump said Washington is aware of the whereabouts of Iranian Supreme Leader Ayatollah Ali Khamenei but currently does not plan to "eliminate" him.

Trump also demanded Iran's "unconditional surrender", though he said he would prefer to avoid deploying military force despite Washington's patience "wearing thin" following Israeli strikes on Iranian targets.

Peskov said that Russia's reaction to any potential assassination attempt on Iran's supreme leader will be sharply negative. "We would strongly condemn such an act," he said.