Meeting the Taliban in Qatar, General Mark Milley "discussed the need for an immediate reduction of violence and (to) accelerate progress towards a negotiated political solution which contributes to regional stability and safeguards US national interests," spokeswoman Commander Sarah Flaherty said.

The chairman of the Joint Chiefs of Staff, who was meeting for the second time with Taliban representatives, also held talks in Kabul with President Ashraf Ghani, she said.

The trip comes as outgoing President Donald Trump speeds up the US withdrawal, part of his effort to wind down "endless wars."

President-elect Joe Biden has long agreed on the need to end America's longest war but it remains to be seen if he sticks to Trump's timeline, and he has called for a residual force to remain in Afghanistan for counterterrorism operations.

Under a February 29 agreement reached in Doha, the United States set in motion a withdrawal and the Taliban agreed not to let Afghanistan be used by extremists -- the original reason for the US invasion following the September 11, 2001 attacks.

The Taliban have since held fire on US troops but not on Afghan forces, although the Islamist militants have also for the first time opened talks with the internationally recognized government, which it considers illegitimate.

The talks recently managed to clear a key sticking point on the nature of the negotiations but there has been no progress on substantive matters.

The Afghan talks are on hiatus until January 5, with the government team returning to Kabul for the new year to consult.