SEOUL, South Korea — An American man detained by North Korea after allegedly entering the communist country illegally has sought asylum and wants to join its military, a news report said Saturday.

South Korea’s Dong-a Ilbo newspaper said the man crossed into North Korea from China on Monday.

It said an unidentified source in North Korea told the newspaper the 28-year-old man said he came to the country because he did not “want to become a cannon fodder in the capitalist military,” and “wants to serve in the North Korean military” instead.

The National Intelligence Service, South Korea’s top spy agency, said it could not immediately confirm the report. The U.S. Embassy in Seoul said it had no such information.

On Thursday, the North’s official Korean Central News Agency reported an American was arrested Monday for trespassing and his case was under investigation.

It was the second case of a detained American in North Korea in the past month, further complicating a relationship that has been badly strained for years over North Korea’s pursuit of nuclear weapons and periodic testing of missiles in defiance of repeated U.N. Security Council warnings.

In Washington, State Department spokesman P.J. Crowley said the North Koreans, in a bare-bones message through their representative at U.N. headquarters in New York, provided no identifying information about the detainee.

Crowley said the U.S. has asked Swedish government intermediaries to gain access to the detainee. The Swedish Embassy in Pyongyang represents U.S. interests there as Washington has no diplomatic relations with the North.

In late December North Korea said it was holding a U.S. citizen for illegally crossing the North Korea-China border. It did not identify the man, but the State Department has said he is Robert Park, an American missionary.

South Korean activists say Park entered the North on Christmas Day to raise the issue of human rights and call on its leader, Kim Jong Il, to step down and free hundreds of thousands of people reportedly held in political camps.

Last year, North Korea freed two U.S. journalists — who had been sentenced to 12 years of hard labor for trespassing and “hostile acts” — to former President Bill Clinton during a visit to Pyongyang.