US Defence Secretary James Mattis and Nato chief Jens Stoltenberg in Kabul

US Secretary of Defence Mattis chats with Nato Secretary General Stoltenberg during a Nato defence ministers meeting in Brussels.

KABUL (AFP) - US Defence Secretary James Mattis arrived in Kabul on Wednesday (Sept 27), an AFP reporter said, along with Nato chief Jens Stoltenberg, weeks after US President Donald Trump's pledge to send more troops to the war-torn country.

General Mattis is the first member of Mr Trump's Cabinet to visit Afghanistan since the strategy announcement to keep American boots on the ground there indefinitely.

The unnanounced high-level visit comes as Afghan security forces struggle to beat back the Taliban, which has been on the offensive since the withdrawal of US-led Nato combat troops at the end of 2014.

The resurgent militants have promised to turn Afghanistan into a "graveyard" for foreign forces and have been mounting deadly attacks as they maintain control over large swathes of the country.

US generals have for months been calling the situation in Afghanistan a "stalemate", despite years of support for Afghan partners, continued help from a Nato coalition and an overall cost in fighting and reconstruction to the US of more than US$1 trillion (S$1.4 trillion).

The war turns 16 next month, and is America's longest-ever conflict.

Join ST's Telegram channel and get the latest breaking news delivered to you.