Iraq's Kataib Hezbollah militia has threatened to increase attacks on U.S. forces in the country, in response to the airstrike targeting the Hashd al-Shaabi group on the Iraq-Syria border on late Sunday.

"Extremism in the attitude and approach of the U.S. should be responded to with action, not condemnation," Abu Ali al-Askari, a senior Iraqi Kataib Hezbollah commander, said in a Telegram message on Monday.

He called for increasing attacks on the "enemy's" headquarters and bases.

Al-Askari also called on Iraqi security forces to cooperate with militias to liberate the country's territories from the "occupier."

Earlier Monday, the U.S. announced in a statement by Pentagon spokesperson John Kirby that it launched targeted airstrikes "against facilities used by Iran-backed militia groups in the Iraq-Syria border region."

Iraq's national security cabinet Monday condemned the airstrike, considering the strike "a blatant violation" of Iraq's sovereignty. A statement following a security cabinet emergency meeting, headed by Iraqi Prime Minister Mustafa al-Kadhimi, said Iraq will "study all legal options to prevent the repetition of such attacks."