The US is stepping up its anti-Isis military campaign in Iraq shortly after the Paris talks.

The latest airstrikes have pounded targets near the capital Baghdad.

The US Central Command said American warplanes launched airstrikes in the south of Baghdad at the request of Iraqi ground forces.

This is the first round of airstrikes after the Paris conference, where more than 40 nations pledged to support the US-led campaign against Isis.

The US has conducted more than 150 airstrikes in Iraq since 8 August, but most of them are intended to protect American interests.

The latest offensive appears to be the first time US forces have been involved in an operation directly to help Iraqi forces.

"These strikes were conducted under authority to protect US personnel and facilities, support humanitarian efforts, and help Iraqi forces on the offensive against ISIL terrorists," said the US Central Command.

"The air strike southwest of Baghdad was the first strike taken as part of our expanded efforts beyond protecting our own people and humanitarian missions to hit ISIL targets as Iraqi forces go on offense, as outlined in the president's speech last Wednesday."

Separate airstrikes also targeted key Isis positions near Mount Sinjar destroying six vehicles.