Philippine President Rodrigo Duterte has restored a crucial pact governing the presence of U.S. troops in the Philippines, the two countries' defense ministers said on Friday, reversing a decision that had caused increasing concern in Washington and Manila.

The Visiting Forces Agreement (VFA) provides rules for the rotation of thousands of U.S. troops in and out of the Philippines for war drills and exercises. It has assumed additional importance as the United States and its allies contend with an increasingly assertive China.

Philippine Defense Secretary Delfin Lorenzana said he was unsure why Duterte had reversed himself but made the decision after meeting U.S. Defense Secretary Lloyd Austin in Manila on Thursday.