A local court in military-ruled Myanmar on Friday sentenced American journalist Danny Fenster to an 11-year jail term, in a major setback to U.S. efforts to get him released, according to a Reuters report.

Fenster, 37, managing editor of online magazine Frontier Myanmar, was found guilty of incitement and violations of immigration and unlawful associations laws, his magazine said, describing the sentences imposed as "the harshest possible under the law".

"There is absolutely no basis to convict Danny of these charges," said Thomas Kean, editor-in-chief of Frontier Myanmar.

Fenster was arrested while trying to leave the country in May and has since been held in Yangon's notorious Insein prison. His family has repeatedly called for his release.

Fenster's trial had not been made public and a spokesman for the junta did not immediately respond to a request for comment.

Fenster is among several journalists who were detained in Myanmar after protests and strikes surged against the coup.

The United States has been pushing for Fenster's release. The US State Department had earlier said his detention was "profoundly unjust" and "plain for the world to see", urging the junta to release him immediately.