LONDON: British Prime Minister Gordon Brown urged Pakistan on Sunday to step up its action against Al-Qaeda and hunt down leader Osama bin Laden and his deputy Ayman al-Zawahiri.

"We have got to ask the Pakistani security forces, army and politicians to join us in the major effort that the world is committing resources to, not only to isolate Al-Qaeda but to break them in Pakistan," Brown told BBC television.

He added: "The Pakistan government has started to take on the Taliban and to take on Al-Qaeda in South Waziristan.

"But we have got to ask ourselves why, eight years after September 11, nobody has been able to spot or detain or get close to Osama bin Laden, nobody has been able to get close to Zawahiri, the number two of Al-Qaeda."

Pakistan's prime minister, Yousuf Raza Gilani, will visit Britain on Thursday and hold talks with Brown at Downing Street.

Brown continued: "I will be talking, as I have over the last few days, to all the senior leaders in Pakistan and saying if we are putting our strategy into place for dealing with building up Afghan forces in Afghanistan so they can control things themselves, then Pakistan has got to be able to show that it can take on Al-Qaeda, which is a threat to Pakistan and the Pakistani people as well as to the rest of the world.

"We have got to focus the attention of the world on the continuing threat from Al-Qaeda. As I have said, three-quarters of terrorist plots that threaten Britain arise from that area of Pakistan.

"I believe that after eight years, we should have been able to do more, with all the Pakistani forces working together with the rest of the world, to get to the bottom of where Al-Qaeda is operating from.

"I want to make sure that the Pakistani army and Pakistani security services, as well as the Pakistani politicians, will make sure that in South Waziristan we are taking on Al-Qaeda directly."

Brown acknowledged that progress had been made but stressed that Britain wanted more done to hunt down the two top Al-Qaeda chiefs.

"Progress has been made... but we want, after eight years, to see more progress in taking out these two people at the top of Al-Qaeda, who have done so much damage and are clearly the brains behind many of the operations aimed at Britain."