Pakistan has pledged to cooperate fully with India and the U.S. in the fight against terrorism, a top Obama Administration official has said. They (Pakistan) have pledged to continue to cooperate fully with the U.S. and also to cooperate fully with India, both in terms of ongoing investigations, making sure that those who have perpetrated past crimes are brought to justice, and that together that the countries in the region reduce and ultimately eliminate this threat that threatens all of them, said P. J. Crowley, the Assistant Secretary of State for Public Affairs. Talking to reporters at his daily news conference, Mr. Crowley said the Obama Administration is concerned about the presence of extremist groups in South Asian countries. This has been a part of our ongoing dialogue with Pakistan. It came up in the discussion that Secretary Clinton had earlier this week with Prime Minister Gilani. I just simply would say that we emphasise again this is a shared struggle. We believe very strongly in the aggressive steps that Pakistan is taking, Mr. Crowley said. Mr. Gilani was recently in the U.S. to attend the 47nation Nuclear Security Summit convened by Mr. Obama to secure loose nuclear materials in the next four years. The U.S. President and Ms. Clinton met Mr. Gilani on the sidelines of the summit. Indian Prime Minister Manmohan Singh too was in Washington to attend the summit and met Mr. Obama last Sunday, besides having two brief encounters with Mr. Gilani. At a press briefing before leaving the U.S., Dr. Singh had said India will resume talks with Pakistan only after Islamabad takes action against those responsible for the Mumbai attacks.