The media agency said Gomes confessed to all charges.
Gomes, a Boston resident, was arrested Jan. 25 after entering the country from the China border. He had previously worked as an English language teacher in a town north of Seoul. His colleagues and friends say he is a devout Christian.
It is also known that he participated in at least two demonstrations calling for the release of American Christian activist Robert Park, who was arrested in December after illegally entering North Korea.
After several months, it is still unclear what motivated Gomes to enter North Korea or how he managed to make the crossing.
Gomes' imprisonment briefly overlapped with that of Park, who was released in February.
A March 24 statement attributed to Park, released by fellow anti-North Korean activist Norbert Vollertsen, said: "Robert Park begs the American government to intervene on Mr. Aijalon Gomes' behalf … Mr. Gomes is one of the most kind, gentle, beautiful and good persons Mr. Robert Park has ever met," according to CNN.
The U.S. State Department has not yet released a statement addressing the sentence against Gomes.
Officials from the Swedish Embassy in Pyongyang, which represents U.S. interest in North Korea, attended the court hearing on Tuesday. The United States has no diplomatic relations with North Korea.
Gomes is the fourth American to be arrested by North Korea since 2009.
American journalists Laura Ling and Euna Lee were arrested last March and sentenced to 12 years of hard labor. The journalists, however, were released when former U.S. President Bill Clinton met with Kim Jong-il in Pyongyang on their behalf.
Then in December, Korean-American Robert Park, who proclaimed the Gospel while crossing the border on Christmas Day, was arrested for trespassing. He was released after less than two months. The state media said the country decided to "leniently forgive" Park after he acknowledged that he was wrong about North Korea and repented.
Park has not made any public appearances after his release. Fellow activists told South Korean media that he was allegedly sexually abused while being held in the North, and that he was undergoing treatment at a mental institution in America, according to CNN. Park was not formally indicted with any charges by the North.
Experts on North Korea say that the government is unlikely to send Gomes to hard labor camp, but intends to use the sentence to pressure Washington to engage in direct negotiations.
Pyongyang is under growing pressure to return to six-party talks on nuclear disarmament.