VIETNAM-US-DIPLOMACY-DEFENCE

A Vietnamese soldier stands next to a hazardous warning sign by a runway at Bien Hoa air base, on the outskirts of Ho Chi Minh City, as US Defence Secretary Jim Mattis visits the former US air base on 17 October, 2018. (Photo: Thomas WATKINS/ AFP)

A Vietnamese soldier stands next to a hazardous warning sign by a runway at Bien Hoa air base, on the outskirts of Ho Chi Minh City, as US Defence Secretary Jim Mattis visits the former US air base on 17 October, 2018. (Photo: Thomas WATKINS/ AFP)