"We strongly condemn this indiscriminate attack on civilians. We extend our deepest condolences to the families and friends of the victims of this senseless violence. We wish those who were injured a full and speedy recovery," said Mark Thornburg, a State Department spokesperson.
"The United States remains steadfast in its commitment to the people of Pakistan in their efforts to counter terrorism and build a peaceful future," Thornburg said in response to a question.
At present, the US has no reports of an American citizen among the casualties of the attack in Islamabad, he said.