ISTANBUL — Turkey’s defense minister said Thursday that Kurdish forces in Syria would be “buried” in their trenches in any Turkish operation to rout the fighters from the border, just one day after President Trump announced a withdrawal of U.S. troops from the country.

Speaking from the Qatari capital, Doha, Hulusi Akar said Turkey was preparing “intensely” for a military offensive east of the Euphrates River in Syria, where Kurdish-led forces have battled the Islamic State militant group.

The fighters have dug trenches and tunnels in the area in anticipation of the operation, Akar said, according to Turkey’s official Anadolu news agency.

“But whatever they dig . . . when the time comes they will be buried in the trenches,” he said. “Of this there should no doubt.”

The Trump administration is planning to withdraw all U.S. troops from Syria immediately. The president tweeted Dec. 19 that the U.S. had defeated ISIS in Syria. (Jason Aldag/The Washington Post)

Trump has ordered a full withdrawal of U.S. troops from Syria, where they have partnered with the Kurdish-led Syrian Democratic Forces to oust Islamic State fighters.

That alliance has long angered Turkey, which sees the ethnic Kurdish forces as an existential threat to Turkish territory. Turkish officials say that the fighters are linked to separatist Kurdish militants inside Turkey, where the two sides have waged a decades-long war.

Trump’s decision came just one week after the Pentagon called unilateral action by Turkey in northeastern Syria “unacceptable.” The United States has roughly 2,000 troops stationed in Syria, which is reeling from a bloody civil war.

Turkey this year backed an operation by its Syrian rebel proxies to eject Kurdish forces — also known as the YPG, or People’s Protection Units — from the city of Afrin. Elsewhere in northern Syria, Turkey has conducted patrols with U.S. troops in areas previously under YPG control.

“We are following developments closely,” Akar said Thursday, without mentioning the U.S. withdrawal. He said Turkish intelligence and operational units are working “day and night” to prepare for the offensive.