The UK is to send up to 50 additional military personnel to Afghanistan to train and advise security forces there.

They will join the 450 British troops already in the country - and will aid counter-terrorism efforts and provide leadership training.

It comes as Nato allies agreed to maintain a stable military presence in Afghanistan, bolstered by President Barack Obama's decision to make a smaller cut in US troop levels than he had initially planned.

Nato secretary general Jens Stoltenberg said the allies also made commitments to continue to fund the Afghan security forces through until 2020, and are "close to" the five billion dollars (£3.8 billion) per year needed.

"We are very close and I am certain we will reach that level," Mr Stoltenberg told reporters following a meeting on Afghanistan on the second day of a Nato summit in Poland.

Mr Obama has been urging Nato leaders gathered in Warsaw to expand their support for the war against the Taliban.