"We are still involved in trying to get a negotiated settlement. The Taliban have not met their commitments," said Pentagon spokesman John Kirby.

Kirby said the new administration of President Joe Biden remains committed to the February 2020 peace agreement set in Qatar between the United States and the Afghan insurgent group.

That agreement required the Taliban to halt attacks on US forces, sharply decrease the level of violence in the country, and advance peace talks with the government in Kabul.

In return, the United States would steadily reduce its force level in the country, and remove all forces by May 2021.

Kirby said there is "no change" to the US commitments made in the peace deal.

However, he said, "the Taliban are not meeting their commitments to reduce violence, and to renounce their ties to Al-Qaeda."

As long as that remains the case, he said, "it's going to be difficult for anybody at that negotiating table" to stand by their own promises.

"In fact, it would not be the wise course," he added, underling the US commitment to ending the war "in a responsible way."

Kirby said the US Defense Department is comfortable with the current level of 2,500 US troops in the country, down from close to 13,000 a year ago.

It is enough to carry out the main US mission in the country now, to counter the Islamic State and Al-Qaeda forces operating in Afghanistan, he said.

But he would not say if the Pentagon would cut troop levels to zero by the May deadline.

Much depends on whether the Taliban and the Afghan government can negotiate a peace settlement, he said told reporters in a briefing at the Pentagon.

"I would say this to the leaders of the Taliban, that... they make it that much more difficult for final decisions to be made about force presence by their reticence to commit to reasonable, sustainable and credible negotiations at the table," he said.