MANILA, Dec. 17 -- The Philippine government expressed disappointment on Wednesday over the U.S. decision rejecting Manila's request to turn over to its custody an American serviceman charged for murdering a Filipino transgender.

Quoting Foreign Affairs spokesman Charles Jose, Presidential Spokesperson Edwin Lacierda said the Aquino administration expects Washington to honor its obligations under the Visiting Forces Agreement (VFA) and ensure that Joseph Scott Pemberton is made available for all required appearances before the appropriate Philippine authorities as related to the investigation and trial concerning the allegations with which the U.S. Marine has been charged.

"We are disappointed that the U.S. has chosen to invoke their rights under the VFA to maintain custody of the accused," he said.

But Lacierda said Pemberton will remain detained in sovereign Philippine territory, and the Armed Forces of the Philippines will actively participate in ensuring that he remains in the agreed detention facility.

"We will continue to make the necessary representations in support of the judicial process. We will also remain vigilant in ensuring that the U.S. continues to remain faithful to their obligations under the VFA, to ensure that justice is obtained," he said.

Pemberton, 19, is accused of murdering Jeffrey "Jennifer" Laude, 26, a Filipino transgender woman, on Oct. 21 in a motel in northern Philippine city of Olongapo.

On Tuesday, the Olongapo City Prosecutor's Office issued a warrant of arrest against Pemberton.