Gordon Brown goes to Afghanistan for the publicity.

[FL Patriot]

Gordon Brown wears a helmet and body armour as he leaves 'Little Heathrow' at Kandahar airbase. Photograph: Matt Cardy/Getty Images

Gordon Brown made a surprise visit to Afghanistan today to meet British troops and attempt to patch up his fractious relationship with the country's president, Hamid Karzai.

The prime minister said the next few months would be "critical" and urged the Afghan government to take a bigger role in fighting the Taliban.

The visit included an overnight stay at Kandahar airfield, the coalition headquarters for the region, wherethe Brown stayed in a pre-fabricated, corrugated shed, surrounded by concrete blast walls. There was a nearby concrete shelter for him to repair to in the event of a rocket attack on the camp.

It was the first time a British leader had stayed overnight in either Afghanistan or Iraq, and came at the start of a surprise pre-Christmas visit to the troops.

Brown said: "I wanted to be here with the troops to thank them for what they are doing. I wanted to see what it was like working with them."

In a joint press conference Brown and Karzai denied suggestions of a rift, claiming he and Karzai had always had "the best relations". Karzai said he was "happy and honoured" to call the prime minister a friend. It was a "very, very trustworthy relationship".

Brown has been prominent among world leaders in voicing criticism of Karzai's government, following his August re-election in a vote marred by widespread fraud.

The Afghan leader hit back in an interview last week, saying comments from Brown were "very unfortunate and very artificial. It is extremely insulting".

Asked this morning about corruption in the Kabul administration, Brown said Karzai had drawn up plans that would include improving governance that he would present to the London conference on Aghanistan next month.

"I do want to reassure families of those who are serving in Afghanistan and families mourning people lost in Afghanistan that the cause that we are fighting comes directly to the streets of Britain," Brown said.

Karzai said he was "very, very sorry" when he saw British troops killed or wounded in Afghanistan and said he was aware of the "consequences" in Britain.

Brown was briefed late last night and earlier this morning by senior military staff in Kandahar as well as meeting regular troops and inspecting new equipment.

Last week saw the 100th British soldier killed in Afghanistan this year, prompting further controversy and debate over Britain's role in the country. This year has been the bloodiest for British forces since the Falklands War in 1982.

Brown said today he was "more confident" about the conflict following recent additions of equipment and the increases in troop numbers announced by himself and the US president, Barack Obama.

He paid tribute to the troops' "bravery, professionalism and dedication". "I know this has been a difficult year," he said, acknowledging that casualties have been "high". But he maintained that morale among the troops was good.

About 1,500 improvised explosive devices have been detected and dismantled in the past six months, the PM added, as efforts have been stepped up to counter the threat.

He went on: "I think the next few months are obviously critical. We need to show there is support for our forces back in Britain, which I know there is, and a determination to take on the Taliban."