The United States Army confirmed reports on Monday that Russia has detained an American soldier.

“On May 2, 2024, Russian authorities in Vladivostok, Russia, detained an American soldier on charges of criminal misconduct,” Army Spokeswoman Cynthia O. Smith said in a statement:

The Russian Federation notified the U.S. Department of State of the criminal detention in accordance with the Vienna Convention on Consular Relations. The Army notified his family, and the U.S. Department of State is providing appropriate consular support to the soldier in Russia. Given the sensitivity of this matter, we are unable to provide additional details at this time.

The soldier was detained in Russia after he had traveled there on his own from South Korea, where he was stationed, according to NBC News, which first reported his detention.

The soldier was not on official business, according to the network. He is accused of “stealing from a woman,” officials said.

The soldier joins fellow Americans — Wall Street Journal reporter Evan Gershkovich and former Marine Paul Whelan — as detainees in Russia. Gershkovich was detained and jailed in March 2023, and Whelan was arrested in 2018.

Tensions are high between the U.S. and Russia. The U.S. is flowing billions in military and economic aid to Ukraine, which is engaged in a hot war with Russia.

The detention of a U.S. soldier in Russia threatens to bring relations even lower and weaken U.S. support for Ukraine, during already growing opposition.

Chairman of the House Foreign Affairs Committee Rep. Michael McCaul (R-TX) said he was “deeply concerned” by the detention.

“I am deeply concerned by reports that a U.S. Army officer has been detained in Russia. Putin has a long history of holding American citizens hostage. A warning to all Americans—as the State Department has said, it is not safe to travel to Russia,” McCaul said in a statement.

CHM @RepMcCaul: “I am deeply concerned by reports that a U.S. Army officer has been detained in Russia. Putin has a long history of holding American citizens hostage. A warning to all Americans—as the State Department has said, it is not safe to travel to Russia.” https://t.co/R4lIdjmDOH

— House Foreign Affairs Committee Majority (@HouseForeignGOP) May 6, 2024