Obama: Campaign against IS militants 'will not be quick'

President Barack Obama says there has been progress in the campaign against Islamic State militants, but has emphasised ''it will not be quick''.

Speaking at a Pentagon briefing, the US president said that the task was largely up to local forces on the ground - but that losses in Syria and Iraq proved that the militants could be defeated.

''Our coalition has now hit Isil [Islamic State] with more than 5,000 airstrikes, we've taken out thousands of fighting positions, tanks, vehicles, bomb factories and training camps,'' he said.