"We've made a lot of progress. We're talking," Trump told reporters at the White House.

Trump said that US forces, bogged down for nearly two decades, "could win Afghanistan in two days or three days or four days, but I'm not looking to kill 10 million people."

He made a similar comment about 10 million casualties in July, but this time specified that this would not involve nuclear weapons. "I'm talking conventional."

Trump was vague, however, in answering a question about a Washington Post report on a deal being brokered in which the United States would cut troop levels in Afghanistan to as low as 8,000 from their current 14,000.

In return, the Taliban insurgency would cease fire, enter peace talks with the US-backed Afghan government, and pledge to keep out Al-Qaeda, whose 9/11 attacks on the US spurred the invasion that ousted the Taliban from power in Afghanistan in 2001.