Britain will send a small contingent of expert troops to Iraq to help coalition forces drive out Islamic State jihadists, Defence Minister Michael Fallon said Thursday.

"We are stepping up our contribution to the fight against Daesh (IS) and fulfilling Britain's role as a key player in the global coalition," Fallon said in a statement.

"These extra troops will help support operations to bring the defeat of Daesh a step closer."

The 44 Royal Engineers are to be deployed for six months at the Al-Asad airbase in Anbar Province, in western Iraq, to build infrastructure including accommodation and offices.

This brings the number of British troops at the airbase to more than 300 and the total in Iraq to around 600.

The airbase also houses hundreds of US advisers as well as Iraqi and Danish troops.

Anbar, a sprawling desert province that borders Syria, Jordan and Saudi Arabia, has long been an insurgent stronghold, and IS already controlled parts of it when it swept through Iraq in 2014 to take control of roughly a third of the country.

Pro-government forces have since retaken most towns and cities in Anbar, but the jihadists still hold several areas along the border with Syria.

Earlier Thursday, Iraq declared that its forces had retaken the northern city of Tal Afar and the surrounding region of Nineveh, in another victory against the jihadist group.

IS now controls barely 10 percent of the country, according to the US-led international coalition ranged against the jihadists.