A U.S. Marine admitted in court Monday to choking but not killing a transgender Filipina in self-defense last year, in a case that could test the strength of security ties between the Philippines and the United States.

Lance Cpl. Joseph Scott Pemberton, who is being held at a U.S. facility at the main Army base in Manila, has been charged with the murder of Jennifer Laude — also known as Jeffrey Laude — who was found dead on Oct. 11 in a hotel in Olongapo City, near a former U.S. naval base north of Manila.

Pemberton told the court he acted in self-defense after he discovered that Laude, who was performing oral sex on him, was a transgender woman and pushed her away.

Pemberton, who was 22 at the time, said Laude, 26, slapped him, causing him to respond “in defense,” said Pemberton's lawyer Rowena Flores.

“After some time, to subdue Jeffrey, Joseph Scott Pemberton held his [Laude's] head under his armpit. Jeffrey stopped moving. Joseph Scott Pemberton tried to revive him,” Flores added, saying Pemberton left Laude “alive in the bathroom.”

But Harry Roque, a lawyer representing the victim's family at the trial, said Pemberton “dragged her to [the] bathroom and dumped her.”

The trial is off-limits to the press. Pemberton faces a jail term of 20 years to life if found guilty, and a verdict is expected next month. He had just taken part in joint U.S.-Philippine military exercises nearby when the alleged killing occurred.

The case, being heard by a court in Olongapo, could sway public opinion in the Philippines against a new defense cooperation deal signed with the U.S. last year, testing relations as the two allies face growing tensions in the South China Sea with an increasingly assertive China.

The pact allows the U.S. military to store supplies in Philippine bases for operations related to maritime security, humanitarian assistance and disasters, but the deal is being questioned before the Philippine Supreme Court.

Wire services