Rep. David Cicilline (D-R.I.) urged Secretary of State John Kerry to assist Marine Sgt. Andrew Tahmooressi, who has been jailed in Mexico for more than six months.
Mexican authorities arrested Tahmooressi in March 2014 after he crossed the U.S.-Mexico border with weapons and ammunition in his car.
During a rare recess hearing of a House Foreign Affairs subcommittee on Wednesday, Tahmooressi's mother pleaded for President Obama's help to secure his release. Jill Tahmooressi said that her son suffers from post-traumatic stress disorder and currently faces brutal conditions in the Mexican jail.
Cicilline said the U.S. should use all available resources to secure Tahmooressi's release.
"If Sergeant Tahmooressi's actions were in fact due to PTSD suffered due to his service overseas, we should do everything we can to ensure he is able to return to the United States and receive treatment for his condition," Cicilline wrote in a letter to Kerry.
"It is my hope that, in light of these revelations, you will remain closely involved in this matter and will help ensure that Sergeant Tahmooressi receives the care he needs," Cicilline added.