SEOUL — North Korea on Friday announced the arrest of a university student from Ohio for what it called a ‘‘hostile act’’ orchestrated by the American government to undermine the authoritarian nation.

In language that mirrors past North Korean claims of outside conspiracies, Pyongyang’s state media said the University of Virginia student, entered the country under the guise of a tourist and plotted to destroy North Korean unity with ‘‘the tacit connivance of the US government and under its manipulation.’’ The date of his arrest wasn’t clear.

The North’s official Korean Central News Agency said in a short report that the student, identified as Warmbier Otto Frederick, was ‘‘arrested while perpetrating a hostile act,’’ but it didn’t explain the nature of the act. North Korea has sometimes listed English-language surnames first, in the Korean style. The University of Virginia’s online student directory lists Otto Frederick Warmbier as an undergraduate commerce student, and Wyoming City Schools near Cincinnati confirmed Otto Warmbier is a 2013 high school graduate.

Ohio Governor John Kasich, campaigning in New Hampshire as a Republican presidential candidate, called the arrest ‘‘inexcusable.’’ He sent a message via his Twitter account saying the student ‘‘should be released & returned immediately.’’

A China-based tour company specializing in travel to North Korea, Young Pioneer Tours, confirmed one of its customers, identified only as ‘‘Otto,’’ had been detained in Pyongyang, the North’s capital, but provided no other details.

Social media accounts for Warmbier show interests in finance, travel, and rap music; he was on the University of Virginia dean’s list.

Warmbier was a top student at his high school and was described as a skilled soccer player. Wyoming City Schools spokeswoman Susanna Max said Warmbier was the salutatorian of his graduating class.

The US State Department said in a statement that it was ‘‘aware of media reports that a US citizen was detained in North Korea,’’ but had ‘‘no further information to share due to privacy considerations.’’

An attorney who represented a southwest Ohio man detained by North Korea for nearly six months in 2014 advised caution for those involved with the student.

‘‘They [North Korea] kind of trickle information out, but what’s actually going on can be very different,’’ said the attorney, Timothy Tepe, adding that he learned North Korean authorities monitor reports and comments about detainees. ‘‘You have to be careful what you say.’’

North Korea’s announcement Friday comes amid a diplomatic push by Washington, Seoul, and their allies to slap Pyongyang with tough sanctions for its recent nuclear test. In the past, North Korea has occasionally announced the arrests of foreign detainees in times of tension with the outside world in an apparent attempt to wrest concessions or diplomatic maneuvering room.