Members of the House Foreign Affairs Committee said Wednesday that they believe Mexico will soon release Sgt. Andrew Tahmooressi, the U.S. Marine who has been held prisoner in Mexico after he crossed into that country carrying weapons in violation of Mexican law.

Chairman Ed Royce (R-Calif.) said he met with Tahmooressi in prison back in June, and has continued to press Mexican authorities for his release. Royce said he made a breakthrough in a talk last week with Mexican authorities about Tahmooressi, who has been diagnosed with Post Traumatic Stress Disorder.

Andrew Tahmooressi has been held by Mexican authorities since March 31. (Photo via WSVN-TV)

Andrew Tahmooressi has been held by Mexican authorities since March 31. (Photo via WSVN-TV)

“Last week I had a good and productive conversation with the Mexican Attorney General and am confident that a humanitarian release of Andrew will occur very soon so he can start getting better,” Royce said at the start of a House hearing on the matter Wednesday.

At the hearing, Rep. Matt Salmon (R-Ariz.) added that Mexico’s Attorney General has told lawmakers that Tahmooressi can be released once Mexico receives proof of Tahmooressi’s medical condition. Salmon said lawmakers just sent medical information about Tahmooressi to Mexico, which is why they hope he may soon be able to return home.

“He has the authority within Mexican law to dismiss Sgt. Tahmooressi’s case on humanitarian grounds once he has expert testimony that verifies his combat-specific PTSD diagnosis,” Salmon said. “Chairman Royce and I obtained the appropriate expert medical reports, and forwarded them to the Mexican Attorney General’s desk this past Friday.”

Tahmooressi’s case has frustrated many U.S. lawmakers, in large part because of Tahmooressi’s medical condition, which is difficult to properly treat in Mexico. The Marine has been held in prison since March.

His detention has also led to some frustrations with the Obama administration, which many say has not done enough to press Mexico on Tahmooressi’s release.

“I am mystified that President Obama couldn’t find time, between negotiating with terrorists, to call our ally, the Mexican president, to appeal to him on behalf of our Marine,” Salmon said at the hearing.

“The fact is that Mexican citizens violate U.S. law on a regular and continuing basis, illegally crossing our southern border,” Salmon added. “Mexican officials respond by asking the U.S. for compassion and amnesty for their citizens to remain in the U.S. But frankly, compassion goes both ways.”

By late August, more than 134,000 people had signed a petition asking the Obama administration to demand that Mexico release Tahmooressi. The White House responded that U.S. officials have continued to talk with Mexico in an effort to win his release.

“We respect the rule of law and expect the judicial process of sovereign nations to protect other U.S. citizens who might find themselves in similar circumstances in the future,” the White House said. “We will continue to monitor the case and work with the Mexican authorities as this case proceeds through the Mexican judicial system.”