MANILA — A United States Marine accused in the gruesome killing of a Filipino woman was placed in custody Wednesday on a Philippine military base, in a case that some analysts say could have implications for the two countries’ military relationship.

The Marine, Pfc. Joseph Scott Pemberton, 19, has been identified by the Philippine police as the prime suspect in the killing of Jennifer Laude, 26. Formal charges against Private Pemberton were still being prepared, a prosecutor said.

Some Philippine senators cited the case in calling for a review of the longstanding agreement setting the rules for allowing American military forces to be in the country, including the handling of criminal cases involving them. But the case could also affect a new agreement that would give the United States more latitude in temporarily stationing ships, aircraft, equipment and personnel in its former colony.

The deal is considered crucial to the United States’ efforts to solidify its influence in Asia as China’s power grows. The start of the agreement has already been delayed until the Philippine Supreme Court rules on a case questioning its constitutionality.