Brussels - The United States "wants to work with Pakistan" to boost security along its border with Afghanistan despite the row over US attacks into Pakistani territory, a senior US official said Wednesday in Brussels.

"We want to work with the Pakistanis because we know that long-term stability and security is only going to come from them," US Assistant Secretary of State Richard Boucher told Deutsche Presse-Agentur dpa.

The US is working with Pakistan to help integrate the tribal areas along the border with Afghanistan into the national economy, as well as building the government's military capabilities, he said.

Boucher was speaking at NATO's Brussels headquarters, which he was visiting to brief NATO officials on recent events in Afghanistan and Pakistan.

His visit came on the same day as the chairman of the US Joint Chiefs of Staff, Admiral Mike Mullen, travelled to Islamabad to try and rebuild ties with Pakistan after weeks of increasingly sharp diplomatic exchanges.

US military operations inside Pakistan, including the first known ground raid that killed 20 people on September 3, have fuelled anger in the country, with increasing calls to abandon cooperating with Washington's war on terrorism.

Mullen's visit was "a real attempt to work with the Pakistanis so that between us, the Afghans and the Pakistanis we can all push in on the militants and extremists ... in the border areas," Boucher said.

At the same time, he acknowledged that the US and NATO members will have to put more effort into training Afghanistan's own army, a week after an agreement to boost the force from an originally-planned 80,000 to some 134,000 men.

"Do we have enough (mentoring teams) for the increase? No. Now that we've set a new target we've got to work on the money, the trainers ... (and) plan to not only continue the training we're doing now but extend that training into the future," he said.

"That will require more trainers and (mentoring teams) to get it done right," he said. (dpa)