British Prime Minister David Cameron, left, with his Pakistani counterpart Nawaz Sharif arrive for joint press conference in Islamabad, Pakistan.

Pakistan's Foreign Minister Hina Rabbani Khar speaks during a news conference with Britain's Foreign Secretary William Hague at the Foreign Ministry in Islamabad, Pakistan. Hague s...

British Prime Minister David Cameron bids fare well to visiting Pakistani Prime Minister Yousuf Raza Gilani, right, waving as he leaves 10 Downing Street in London after a meeting....

In this picture taken on June 24, 2011, students of Pakistani Government Girls Comprehensive Higher school study in their classroom in Abbottabad, Pakistan. A group of British scho...

Britain's Prime Minister David Cameron talks with Pakistan's President Asif Ali Zardari at Chequers, his official country residence. President Zardari has been criticised at home f...

Britain's Prime Minister David Cameron talks with Pakistan's President Asif Ali Zardari as they meet at Chequers near Princes Risborough in England.

Asif Ali Zardari is accompanied by his son Bilawal in striped shirt right and daughter Asifa (left) when they arrived at London's Heathrow Airport.

Asif Ali Zardari the President of Pakistan is accompanied by his son Bilawal (in striped shirt right) and daughter Asifa (left) when they arrived at London's Heathrow Airport.

Asif Ali Zardari is accompanied by his son Bilawal and daughter Asifa when they arrived at London's Heathrow Airport. Zardari is set to meet with British Prime Minister David Camer...

Protesters gather outside the Churchill Hyatt Regency Hotel where Pakistan's President Asif Ali Zardari is staying in London. Zardari is set to meet with British Prime Minister Dav...