Istanbul: Iran's foreign minister said on Sunday that Washington is “fully responsible” for what actions the Islamic Republic takes next in retaliation against the US strikes on its various nuclear sites.

“The warmongering, a lawless administration in Washington is solely and fully responsible for the dangerous consequences and far reaching implications of its act of aggression,” Abbas Araghchi said in a news briefing at a conference in Turkiye.

These were the first public statements from a high-ranking Iranian official since the US carried out its strikes.

He also said that Iran will defend itself by all means necessary. "Iran continues to defend Iran's territory, sovereignty, security and people by all means necessary against not just US military aggression, but also the reckless and unlawful actions of the Israeli regime," said Araghchi.

He further added that US and Israel crossed a major red line in attacking Iran's nuclear facilities.

"There is no red line that they have not crossed. And the last one, and the most dangerous one, happened only last night. They crossed a very big red line by attacking nuclear facilities," he said.

Araghchi will also travel to Moscow on Sunday to meet with Russian President Vladimir Putin, the Associated Press reported. Both Iran and Russia have strongly criticised the strikes, calling for restraint and renewed diplomatic efforts.

Details of the agenda have not been publicly disclosed, but the meeting is expected to focus on regional de-escalation, coordination on international diplomacy, and the strengthening of Iran-Russia bilateral relations in the face of growing Western pressure.

This meeting follows a series of diplomatic engagements by Araghchi, including his recent comments condemning Western nations for "blowing up" diplomacy through the use of force.

The Kremlin has yet to issue an official statement on the scheduled talks.

(with inputs from AP and AFP)