Washington dismissed an assertion by fugitive Taliban leader Mullah Mohammad Omar that the United States has been "defeated" in Afghanistan.
"He might want to come in and mention that directly to some of the NATO or American forces there," State Department spokesman Sean McCormack said on Monday.
"I am sure they would be happy to receive him," he said.
The spokesman said that far from being vanquished militarily, NATO forces were succeeding in improving life for the people of Afghanistan.
"This is a country that has a government and people who are dedicated to getting a better future for themselves and not returning to the dark past of the rule of the Taliban," he said.
His remarks came in answer to a statement on Monday attributed by a Taliban spokesman to Omar that "the United States has been defeated in Afghanistan."
"They have been trapped here and are desperately trying to get other countries involved," a spokesman for the militant Islamic leader said in a telephone call from an unknown location.
Omar's statement went on to say that the United States, which led the campaign that toppled the Taliban from government in late 2001, had "invaded" and "occupied" Afghanistan.
"We're fighting to free our country," it said, adding, "We're not a threat to the world."
"The world nations must compel their governments to withdraw from Afghanistan and abandon supporting the United States.