Britain and America are working closely to ensure their Afghanistan strategy is as “clear, as effective and as decisive as possible”, David Miliband has stressed.

The Foreign Secretary was speaking following talks with US Secretary of State Hillary Clinton.

Mr Miliband said the pair had held a “detailed, intensive and productive” meeting in which Afghanistan and Pakistan topped the agenda.

He hailed the “shared strategy” on Afghanistan and said the two countries were working closely together to ensure the coalition effort was “as clear, as effective and as decisive as possible”.

Mr Miliband said critics of the Afghanistan campaign were in danger of “misunderstanding” the discussions taking place between the coalition allies.

President Obama had made it “absolutely clear” that it would always be appropriate to “review the civil and military components of the strategy”. This was a strategy that was “at one” with what the Prime Minister had announced.

Mrs Clinton added: “We have been in office about nine months, we obviously believe the prior eight years were not as effective or as focused as they might have been.”

The two were asked about the security of Pakistan's nuclear arsenal in the face of increasing Taliban attacks on its military and security apparatus. They said that while the country faced a serious threat from terrorism the arsenal was not at risk.

Mr Miliband said: “The insurgencies that Pakistan faces are a mortal threat to that country but it is a threat that over the last three or four months the Pakistan military and the Pakistan people have shown enormous resolve and determination and sacrifice in beating back.”

He added: “There is no evidence that has been shown...of any threat to the Pakistani nuclear facilities. It is very important that alarmist talk is not allowed to gather pace.”

Mrs Clinton said: “We have confidence in the Pakistani government and military's control over nuclear weapons.”

She said terrorists were “increasingly threatening the authority of the state, but we see no evidence they are going to take over the state”.

Iran was also on the agenda with Mrs Clinton stressing that the international community would not wait “indefinitely” for the country to fulfil its international obligations.

Downing Street said later that Mrs Clinton and the Prime Minister had met for about an hour at his country residence, Chequers.

They discussed the strength of the Transatlantic relationship, as well as the situations in Northern Ireland, Afghanistan, Pakistan, India and Europe.