This is a completely unprovoked aggression against Iran, says Putin when he receives Iran's Foreign Minister Abbas Araghchi on Monday.
The Russian president does not, however, promise any concrete support to Iran, which is considered one of Moscow's closest allies in the Middle East.
The Iranian Foreign Minister said on Sunday that the US and Israel have crossed a "great red line" over the weekend, when the US entered the war on Israel's side and attacked Iran's nuclear energy facilities with heavy bunker-busting bombs.
In this new dangerous situation . . . negotiations with Russia can undoubtedly be of the utmost importance, he said on arrival in Moscow.
The Russian Foreign Ministry has previously called the US attacks, which took place during the night to Sunday, "irresponsible" and "a gross violation" of international law.
"It is clear that a dangerous escalation has begun", it said in a statement from the Foreign Ministry on Sunday.
