Iraqi forces say they have driven Islamic State (IS) militants out of the country's largest oil field.

"Iraqi forces... have reached the oil field gates," said Saladin province governor Raad al-Juburi.

Al-Hadath TV reported that security forces had entered the oil field. An Iraqi army colonel confirmed that security forces appeared to be close to regaining control of the field. The victory came just a day after officials announced they had regained control of the nearby town of Baiji, which had been under IS control since June.

The Baiji oil field has seen fighting between IS and Iraqi forces in recent months (photo: Reuters)

Fully liberating the town of Baiji and its oil fields from IS militants would allow Iraqi forces to cut off key IS supply routes.

In another development, the top US military official, General Martin Dempsey, also arrived in Iraq today on a surprise visit. This is his first visit since the US-led coalition began air strikes against IS militants.

Baiji oil field is located 200 km from the capital.

More than 1,000 US troops are in Iraq to help train the national army. President Obama has approved the deployment of up to 1,500 additional troops to support Iraqi forces./.

According to Dan Tri