North Korea notified the U.S. that it has another American in custody for allegedly entering the country illegally, the State Department announced Friday.

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, including the name or gender, or details of the alleged offense.

This is the second case of a detained American in North Korea to surface 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 test-firing of missiles in defiance of repeated U.N. Security Council warnings.

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

On Wednesday, the North's government-run Korean Central News Agency reported that an American had been arrested Jan. 25 for trespassing and that his case was under investigation. It provided no details, and for two days the State Department said it could not confirm the second detention.

Crowley said the North Koreans told the U.S. on Thursday that the latest arrest was of an American who had crossed illegally in North Korea from China. "There is no higher priority than the welfare of our citizens anywhere in the world," the spokesman said.

Crowley said the U.S. is seeking through Swedish government intermediaries to gain access to the detainee to verify the person's condition and details of the incident. The Swedish Embassy in Pyongyang represents U.S. interests there; Washington has no diplomatic relations with Pyongyang.