An appellate court on Thursday upheld the entry ban on a Korean-American singer who has been forbidden to visit South Korea after winning US citizenship in an apparent attempt to evade military conscription.

Steve Yoo, once a mega-hit singer here better known as Yoo Seung-jun, filed a lawsuit against a South Korean consulate in the United States in October 2015 for refusing to grant him a visa.

Upholding a lower court's decision, the Seoul High Court rejected Yoo's appeal and ruled in favor of the consulate's decision.

The Seoul administrative court ruled in September 2016 that the singer's return and resumption of activities here could "demoralize soldiers who are devoting themselves to serving the country and provoke youths into evading conscription."

"The visa issuance was rejected because there was already an entry ban levied on the plaintiff," the appeals court said. "Unless the ban is nullified, we cannot say that there is a fault in rejecting the visa."

The 40-year-old singer's legal representative said they will review whether to again appeal the ruling.

Yoo became a subject of intense public criticism after he was granted US citizenship in 2002, despite his previous promise to the public to fulfill his military duty.

All able-bodied South Korean men must serve in the military for about two years. Attempts to avoid the conscription by young entertainers, as well as the offspring of the rich, are strongly criticized.

Since being barred from entering South Korea, the singer has been active in China. (Yonhap)