Russian President Vladimir Putin told Iran's foreign minister on Monday there was no justification for the US bombing of his country and that Moscow was trying to help the Iranian people.

Putin hosted Iranian Foreign Minister Abbas Araqchi in Moscow two days after US President Donald Trump sent US bomber planes to strike Iran's three main nuclear sites.

"The absolutely unprovoked aggression against Iran has no basis and no justification," Putin told Araqchi in televised comments.

"For our part, we are making efforts to assist the Iranian people," he added.