Washington (CNN) -- A Marine who used his Facebook page to criticize President Barack Obama has been discharged, a Marine Corps spokesman said Wednesday.
Sgt. Gary Stein was given an "other-than-honorable" discharge, said Capt. Brian Block, a spokesman for the Marines.
Among other comments posted to his Facebook page, Stein called Obama a liar and suggested he would not follow some orders issued by the president.
An other-than-honorable discharge is given to a Marine who commits a "serious offense" that significantly differs from conduct expected of a Marine, the Corps said.
A statement from the Marines said it approved the findings of a military board, which in March recommended the discharge.
The board found Stein violated rules limiting political conduct by service members.
The Facebook page for Stein's Armed Forces Tea Party had a post Wednesday saying the discharge will be postponed until the results of a medical condition, with which he was diagnosed Monday, are returned and treatment is discussed.
"I have spent the last 9 years honorably serving this great nation and the Corps," Stein wrote on his personal Facebook page. "Even though I will be discharged no one can take the title of Marine away from me. I thank my family and friends for their support and love. Today is just the start of the rest of my life. Semper Fi."
Stein said earlier this month that the case against him was weak, based on personal opinion and not on legal aspects.
Stein, who is based at Camp Pendleton near San Diego, California, called Obama a liar in a January 26 post to the Armed Forces Tea Party Facebook page. Two days later, he said the president is "the 'Domestic Enemy' our oath speaks about."
In a March 4 posting, Stein questioned Obama's birth certificate. Another discussion on the site in March said Stein would refuse to obey orders given by Obama. He later clarified to say he meant illegal orders, which he has explained as orders such as sending the military to Syria without congressional approval.
"The allegations drummed up against me are no more than an agenda by the Marine Corps to use me as an example," Stein previously said in a statement posted to his page. "If I am guilty of anything it would be that I am American, a freedom loving Conservative, hell bent on defending the constitution and preserving Americas greatness."
While the First Amendment to the U.S. Constitution protects the free speech rights of ordinary citizens, a Defense Department rule prohibits service members from engaging in some forms of political activity.
Among the prohibited activities are publishing partisan political articles or serving in an official capacity with a partisan political club.
Stein has said that he carefully followed the Defense Department directive. The Facebook page notes that it does not represent and is not affiliated with the military or government.
Nearly 30,000 people "like" Stein's Armed Forces Tea Party page.
Facebook members responding to news of Stein's discharge Wednesday were largely supportive.
"You've got to be kidding me. OTH's (other-than-honorable discharges) are given to Marines who grossly violate the UCMJ (Uniform Code of Military Justice), as in drug use, excessive DUI's, adultery, etc. This is a joke," one wrote.
"So disappointed in the Corps. This is a poor decision," wrote another.
Another Facebook member, however, said Stein's punishment was expected.
"For any of you that thought that he was going to get anything but 'Other than honorable' ... you really dont know jack about the military," he wrote.
CNN's Adam Levine contributed to this report.