"We're going down to 8,600 and then we make a determination from there," Trump said in an interview with Fox News radio. "We're always going to have a presence."

Trump also said that if another attack on the United States originated from Afghanistan "we would come back with a force like... never before."

US troops were first sent to Afghanistan after the September 11, 2001 terrorist attacks on US soil carried out by Al-Qaeda, which was sheltered by the former Taliban regime.

Washington now wants to end its military involvement and has been talking to the Taliban since at least 2018. Trump says that troops will only be reduced when the Taliban gives a guarantee that its territory will not be used by Al-Qaeda or other international militant groups.

Trump underlined that there was to be no complete withdrawal, keeping a force that would provide "high intelligence."

"You have to keep a presence," he said.