Defense Secretary Mark Esper said Monday he wants to reduce the number of US troops in Afghanistan "with or without" a peace agreement in order to give higher priority to strategic competition with China.

The Trump administration is expected to announce plans to withdraw around 4,000 troops from Afghanistan, according to US media, after peace talks resumed a week ago between the US and the Taliban.

Esper told reporters Monday that Austin Miller, the head of the NATO mission and US Forces Afghanistan, "is confident that he can go down to a lower number" of troops.

Miller "believes he can conduct all the important counter-terrorism missions and train, advise and assist" the Afghan army, Esper said on a plane as he flew back from Belgium, where he had attended the 75th anniversary of the Battle of the Bulge.

"I would like to go to a lower number because I want to either bring those troops home" to retrain for new missions or to "be redeployed to the Indo-Pacific to face off our greatest challenge in terms of the great power competition that's vis-a-vis China," he said.

"At the end of the day, the best solution for Afghanistan is a political agreement" between the government and the Taliban, Esper added. "But I think we can go down with or without that political agreement."