The US is rushing an initial $5 million in emergency aid to Pakistan to help people uprooted by the fighting against extremists, according to the State Department.
The US had urged the Pakistanis to launch the military action that in recent days has driven hundreds of thousands of people from their villages.
The US Embassy in Pakistan and officials of the US Agency for International Development (USAID) were evaluating the needs of civilians fleeing the Swat valley and surrounding regions in northwest Pakistan, State Department spokesman Ian Kelly said on Tuesday.
"We are of course very concerned about the well-being of civilians who are fleeing the fighting in the area," he said.
"And we have personnel, USAID personnel, on the ground in Pakistan, not in the Swat valley, but in Pakistan, who are directing assistance to help them."
"We've provided a substantial amount of money through the International Organisation for Migration," Kelly said.
"This is primarily to provide tents, provide shelter and emergency relief supplies, food and medicine to the affected populations."
Kelly said the $5 million was just an initial amount.