Washington, September 16 (RHC)-- The Barack Obama administration has launched what it calls the first strikes of its expanded military campaign against the Islamic State. The Pentagon says U.S. warplanes bombed Islamic State positions south of Baghdad in support of Iraqi forces under fire.

The United States had carried out previous strikes under the stated mission of safeguarding U.S. personnel, helping refugees and protecting infrastructure.

The air strikes against the Islamic State in Iraq come as the United States won pledges to fight ISIS at an international summit in Paris. Some 30 countries signed on to a statement vowing to defeat ISIS "by any means necessary."

The United States did not invite Iran to the summit, but confirmed it had reached out with an unspecified offer of cooperation against ISIS. The Iranian government rejected the U.S. overture as "hollow and self-serving" and marred by "evil intentions."

France had wanted to invite Iran to the talks in Paris, but Secretary of State John Kerry said Saudi Arabia and the United Arab Emirates would have boycotted.

Despite the pledges of cooperation, France is the only country to join the U.S. bombing effort so far, launching new surveillance flights over Iraq on Monday.