"According to information available to the US government, Tehreek-e-Taliban plans to conduct attacks against foreigners participating in the ongoing flood relief operations in Pakistan," the official said
The vast floods, which affected millions of Pakistanis need humanitarian assistance at this crucial state. So far US and other nations have donated more than 700 million dollars for relief efforts.
The Pakistani Taliban have earlier denounced all foreign aid for victims of the country's catastrophic flooding.
Despite possible attacks, a top US general overseeing the American military's relief efforts told that US forces had faced no security problems.
He said the Pakistani military "have done a commendable job and a highly effective job in providing our force protection and security while we are here in Pakistan."
Pakistani civilians "are impressed when they see Pakistani military service members and United States military service members working side by side, often flying in the same helicopters, working together on these landing zones..." he said.