Iraqi forces have regained just 270 of the 21,000 square miles controlled by Islamic State in six months, The Pentagon has said.

Efforts to train Iraqi troops and moderate Syrian rebels are moving forward, the US claimed - but so far less than 2% of militant territory has been regained.

Most of this has been taken by Kurdish forces in the north.

Rear Admiral John Kirby, the Pentagon's press secretary, said control of land would continually change over time. He added that it would be a long struggle.

One success of the campaign against IS has been in the Syrian town of Kobani, where a large number of airstrikes have helped Kurdish forces gain 70% control.

The town had been on the brink of collapse.

The Rear Admiral said training of Iraqi forces was now taking place at all four planned sites in the country.

An advance team of no more than 100 US troops will soon head to sites in Saudi Arabia, Turkey and Qatar to begin preparations for the training of Syrian rebels.

Several hundred trainers - including some from host countries - will deploy in the coming weeks, Rear Admiral Kirby said.

"Very productive" discussions have taken place with Syrian groups, though rebels have yet to be actively recruited.

Officials plan to train 5,000 Syrian fighters a year for three years.