The US says it is withholding¹ some $800m in military aid to Pakistan.

美国政府宣称将停止对巴基斯坦8亿美元的军事援助。

White House Chief of Staff Bill Daley told ABC television that Pakistan had "taken some steps that have given us reason to pause on some of the aid".

He said the US raid that killed Osama Bin² Laden³ in May had affected⁴ ties but he insisted the relationship "must be made to work over time".

The $800m (£500m) equates⁵ to about a third of the annual US security aid to Pakistan, US officials say.

In figures submitted to the International Monetary⁶ Fund last autumn, Pakistan's defence expenditure⁷ in its 2010-2011 budget was put at $6.41bn - an increase of $1.27bn on the previous year.

'Difficulties'

Speaking on ABC's This Week programme, Mr Daley accepted that Pakistan had been "an important ally in the fight on terrorism. They've been the victim of enormous amounts of terrorism".

He added: "It's a complicated relationship in a very difficult, complicated part of the world. Obviously, there's still lot of pain that the political system in Pakistan is feeling by virtue⁸ of the raid that we did to get Osama Bin Laden, something that the president felt strongly about and we have no regrets over.

"Until we get through these difficulties, we will hold back some of the money that the American taxpayers⁹ have committed to give them."

The New York Times earlier quoted senior US officials as saying the suspension of military aid amounted to about one-third of the yearly US security assistance to Pakistan.

The paper said the move was to show US anger at the expulsion（驱逐，开除） of US military trainers and to pressure Pakistan to step up its fight against militants¹⁰.

The Times said some of the suspended aid had been earmarked as compensation for Pakistan's redeployment of troops to Afghan border areas to fight militants. Other cuts were in military equipment.

The defence department said in a statement: "The reduced presence of our trainers and other personnel means we can't deliver the assistance that requires training and support to be effective."

The BBC's Rajesh Mirchandani in Washington says this is clearly a strengthening of the US approach to Pakistan - more of the stick than the carrot - but there must be concern that taking away the money will stop the Pakistanis co-operating at all.