British Prime Minister Gordon Brown made a surprise visit to Afghanistan yesterday, where he pledged to speed up the training of Afghan security forces, media reports said.

"I think we could get another 50,000 Afghan army personnel trained over the next year," Brown told the BBC from Helmand province, where the majority of Britain's approximately 9,000 troops in Afghanistan are based.

"Stepping that up means that the Afghans take more responsibility for their own affairs. They're backed up by partnering and mentoring done by the British forces."

The prime minister told reporters that he had made this point in telephone conversations with President Hamid Karzai and Abdullah Abdullah, his main rival in the August 20 presidential elections.

Quicker training could require more British troops, and the BBC reported that Brown discussed this possibility with US commander General Stanley McChrystal.

Amid mounting concern about the British death toll in Afghanistan, which last week reached 207 since the US-led invasion in 2001, the prime minister also highlighted new equipment being brought into the field.

"(This is) new equipment simply to give better protection to our forces and at the same time make them more manoeuvrable," Brown told Sky News. That, working with a big lift in the Afghan forces, is going to be the next stage of the post-election effort in Afghanistan."

During his trip, Brown visited British troops at Camp Bastion in the volatile southern province and thanked them for their efforts in fighting insurgents in the build-up to the presidential election.

This was Brown's fourth trip to Afghanistan in just over a year, a sign of his commitment to the conflict amid signs that public support is waning.