US President Donald Trump has named veteran diplomat John Bass as his choice to become the new US ambassador in Afghanistan, ending his current posting in Ankara.

In a written statement on Thursday, the White House played up Bass's experience in tackling terrorism.

“Mr Bass has spent much of the past decade supporting federal government efforts to mobilise allies and marshal resources to combat terrorism and instability in Iraq, Syria, and Southwest Asia.”

Bass has been posted in Turkey since 2014 and has steered US-Turkey relations through an unsuccessful coup attempt and tensions over Syria and the presence in the United States of a rival to Turkish President Recep Tayyip Erdogan.

His nomination comes as the Trump administration finalises an Afghanistan strategy review that is likely to result in more US boots on the ground.