Pakistans fight against militants has been constrained by the need to deploy troops to help victims of recent devastating floods, the senior US official for Pakistan and Afghanistan said on Tuesday. Ambassador Richard Holbrooke said there was no evidence yet that Islamabad was acting on Washington's demands that it move against the Haqqani group, a Taliban ally which US officials suspect has ties to Pakistani intelligence, and suggested this was because of the country's devastating floods. They have tens of thousands of troops on flood duty. The army has really been the major factor in the rescue effort, and you can't do both things at once, said Holbrooke, who spoke in New York as part of a Reuters Washington Summit. He dismissed suggestions, however, that the Pakistani government's halting response to the flood disaster was creating instability in the country.