The United States will send 560 more troops to Iraq in a bid to step up its campaign against the Islamic State (Isis). The troops will support Iraqi military forces to recapture Mosul from the terror group and use the airbase that was captured recently as a staging ground in the battle against IS (Daesh), US Defense Secretary Ashton Carter said during an unannounced visit to Baghdad.

Carter met US commanders, Iraqi Prime Minister Haider al-Abadi and Defence Minister Khaled al-Obeidi during his visit. The new troops will help in building up the Qayara airbase, about 64km (40 miles) south of Mosul, and include engineers, logistics personnel and other forces.

"These additional US forces will bring unique capabilities to the campaign and provide critical enabler support to Iraqi forces at a key moment in the fight. With these additional U.S. forces, I'm describing today, we'll bring unique capability to the campaign and provide critical support to the Iraqi forces at a key moment in the fight," he added.

On Saturday, Iraqi government forces said they recaptured the airbase with air support from the US-led coalition. They also said that the US air support played a significant role in capturing Fallujah, where over 1,000 IS fighters held out for six weeks against a sustained ground offensive.

Captain Ali Kazwini, an interior ministry official in Falluja told the Guardian "The warplanes were perfect. If it wasn't for them, we would still be here a long time."

IS captured Mosul in June 2014 after driving out the Iraqi army. Mosul is the biggest urban city taken by the terror group in either Iraq or neighbouring Syria.

The Iraqi prime minister vowed to seize it from the militant group by the end of this year but it is not yet clear when an offensive will begin. This addition brings the number of US troops in Iraq to 4,647 and comes almost three months after Obama's last troop addition.

The US Defence Secretary Ash
US Defense Secretary Ash Carter visited Baghdad on Monday and announced that 560 more US troops will be sent to Iraq [File picture]Getty