WASHINGTON The United States said Monday that Pakistani police, in collaboration with the FBI, are conducting a robust investigation to find abducted American development expert Warren Weinstein. (T)he Pakistani Government is cooperating fully with us in trying to find him on the civilian side, State Department spokesperson Victoria Nuland said of Weinstein, 70, who was kidnapped from his home in Lahore on Saturday. Let me say that the Pakistanis are conducting a robust investigation, that it is their investigation but the FBI, our guys on the ground in Pakistan, have been collaborating. And our view is that that cooperation is excellent, she told a news briefing while responding to a series of questions. Gunmen snatched Warren Weinstein before dawn after tricking his guards and breaking into his house in a brazen raid. There are currently no leads as to who is behind the abduction, Ms Nuland told reporters. We dont have anything on who did this. Our priority at the moment is to get this guy back and get him safe, Ms Nuland said as Indian journalists, who always try to cast Pakistan in negative light, asked whether the civilian aid to Pakistan would be affected because of the abduction of the American aid worker. (The US has already put on hold $800 million to Pakistan in security assistance). Its hard to evaluate what lessons one might draw from it until we have more information about the situation, the spokesperson continued. But the Pakistani Government is cooperating fully with us in trying to find him on the civilian side. We consider it very important to continue these (development) programmes which are designed to strengthen Pakistans democracy, economically, politically, to have the kinds of educational and other forms of assistance that will support Pakistans own desire to have a strong democracy going forward. Weinstein is the country director for JE Austin Associates, a development contractor that has received millions of dollars from the aid arm of the US government. He had told his staff that he would be wrapping up his latest project and moving out of Pakistan by Monday. JE Austin Associates stressed Weinsteins commitment to Pakistans economic development in a written statement and said he has worked with a wide range of Pakistani government agencies, including the Pakistan Furniture Development Company and the Pakistan Dairy Development Company. His efforts to help make Pakistani industries more competitive have resulted in many hundreds of well-paying jobs for Pakistani citizens and contributed to raising the standard of living in the communities where these businesses are located, it said. The company also said Weinstein is in poor health and provided a detailed list of medications, many of them for heart problems, that it implored the kidnappers to provide the elderly development expert.