Deputy Prime Minister Nick Clegg confirmed on Tuesday that Britain's combat mission in Afghanistan would be over by 2015 and pledged to protect frontline troops from any sudden cuts in government spending.

Visiting soldiers at Camp Bastion in Helmand province, Clegg also called on Taliban fighters to become part of the political future of Afghanistan.

We have been very clear, we have put a full stop at the end of our engagement, Clegg said. By 2015 there will not be any British combat troops in Afghanistan.

Britain has about 10,000 troops in the war zone and plans to withdraw soldiers from combat duty as part of a broader pullout of NATO coalition troops which will leave Afghan forces in charge of security.

Clegg told the British contingent that a political deal was needed to secure a peaceful future for Afghanistan.

Without a political settlement this is not going to end, he said.

The choice (for the Taliban) is this: they can either carry on fighting ... or they can put down their arms and recognise the Afghan constitution, they can turn their backs on al Qaeda and they can play a role in creating a stable Afghanistan.

The government is reviewing spending across all departments as part of an austerity drive to eliminate a record budget deficit.

Details of where the axe will fall are due to be published in October but Clegg said frontline troops would be protected from sudden changes in funding.

We haven't taken any decisions, he said. But one thing I can be very clear about is that we are not going to suddenly withdraw support from one day to the next to our brave troops who are out here on the front line in Afghanistan.

(Writing by Matt Falloon in London; editing by Keith Weir)