During a trip to Helmand, the prime minister says he hopes to withdraw some British troops next year guardian.co.uk

David Cameron flew into Kabul today for talks with Afghanistan's president, Hamid Karzai, and admitted that leaked diplomatic cables exposing Afghan and US criticisms of Britain's strategy in Helmand had raised "embarrassing questions" for Nato forces fighting the Taliban.

The prime minister is meeting Karzai and General David Petraeus, head of the International Security Assistance Force, after spending last night at Camp Bastion in central Helmand. They are due to discuss progress in Afghanistan – described by Cameron's aides as a "military stock-take" – as well as plans for the transition to an Afghan-led security force.

Cameron is particularly keen to discuss the "reconciliation process" by which forces are now attempting to win round low-level insurgents through offers of better work or lifestyles to sit alongside the military campaign against hardcore Taliban militants. He also announced that £33m from the cross-government Afghanistan fund will be used to refurbish 48 police stations and checkpoints in Helmand.

Yesterday, Cameron visited British and Afghan troops in Helmand, where he declared his "cautious optimism" for the progress being made and revived prospects for withdrawing some troops next year. But he acknowledged the controversy caused by the leak of confidential US diplomatic cables by the WikiLeaks website, was hanging in the air. Karzai, top Afghan officials and the US commander of Nato troops all expressed concerns over the failure of British troops to wrest control of parts of Helmand and connect with local people. Concerns were also expressed about profound and widespread corruption in Afghanistan. All the cables were more than a year old.

Yesterday, Cameron told troops at Camp Bastion: "Of course WikiLeaks has led to lots of embarrassing questions and all the rest of it but I think in the end it doesn't change any of the fundamentals between Britain and America, it doesn't change any of the fundamentals between Britain, America and Afghanistan."

He revealed that he had Sunday lunch with the US ambassador to London before flying to Afghanistan. "The British-American relationship is incredibly strong," Cameron said. "When you look at actually what was said it was relating to a previous period where we all know now there weren't enough troops in Helmand. We came in 2006 with a few thousand troops there are now 30,000 troops in Helmand."

General Sir David Richards, the chief of defence staff, addressing a press conference with Cameron, added: "At no stage were they criticising our forces abilities it was all about our inability to produce the force rations the PM has been talking about since."

Karzai was described in one cable from the US ambassador Karl Eikenberry as having an "inability to grasp the most rudimentary principles of state-building" and having a "deep-seated insecurity" as a leader.

Asked about Karzai, Cameron said: "Of course there will be areas of frank exchanges of views, areas of disagreement but I've met President Karzai consistently over the past five years and got to know him. You have to appreciate that of course there are times of frustrations, but you have to appreciate that we want someone who is going to speak up for Afghanistan and who wants to take control of Afghanistan and who wants an Afghanistan without foreign forces on the soil. That's in our interest as well as his interest."