Washington's involvement in the Philippine drug war and activity in the South China Sea were in focus as Trump visited Manila.
Beijing has begun testing a powerful new dredger ship capable of creating artificial islands, which many fear could be used in the South China Sea.
Companies with energy interests in disputed areas of the waterway could face harassment from China if they don't meet Beijing's demands.
An American business group has endorsed on Friday the ex-U.S. version of a trade deal that Trump dismissed as a “disaster.”
Beijing may be using underwater drones to strengthen its ambitions in the South China Sea.
Beijing warned Hanoi that it would attack Vietnamese bases in the Spratly Islands if drilling continued, the BBC says.
Indonesia is defending its maritime rights within the South China Sea in a perceived move against Chinese encroachment.
Two U.S bombers have flown over the disputed South China Sea, the U.S. Air Force said on Friday.