The Iraqi prime minister Haider al-Abadi has urged Islamic State (IS) militants fighting in Mosul to lay down their weapons even as the Iraqi security forces drove reached within a few km of an airport on the edge of the city.

Speaking on a visit to the front line to the east of the city, Haider al-Abadi said told people in Mosul: "we will liberate you soon".

The city has been under IS control for more than two years.

Al-Abadi called on IS fighters to surrender after government forces gained a foothold in Mosul's eastern suburbs, said a BBC report.

"My message to IS, if they want to save their lives, they should lay down their weapons now," the prime minister told reporters.

Government forces on Saturday also gained control of Hammam al-Alil, about 15 km south of Mosul on the Tigris river, despite fierce resistance, the army said.

The advance on the southern front comes days after Iraqi special forces fought their way into the eastern side of Mosul, taking control of six neighborhoods according to Iraqi officials and restoring a foothold in the city for the first time since the army retreated ignominiously two years ago.