The leader of an online chat group apparently behind the leak of sensitive Pentagon documents on the Ukraine war is a 21-year-old Massachusetts Air National Guardsman, the multiple media outlets reported Thursday.

The New York Times and Wall Street Journal, citing documents and U.S. officials, identified the leader as Jack Teixeira, who oversaw a private online group named Thug Shaker Central, where a group of mostly young men and teenagers "shared love of guns, racist online memes and video games," the Times reports.

The Defense Department issued a statement: “We are aware of the investigation into the alleged role a Massachusetts Air National Guardsman may have played in the recent leak of highly-classified documents.”

Teixeira was based at Fort Bragg at the time of the leak, U.S. officials told the Wall Street Journal, and an arrest could be made as early as Thursday. Reuters said the arrest would take place in Massachusetts.

Members of the group told the Times that the airman was not a whistleblower, and the secret documents were never meant to go beyond their group. Two U.S. officials confirmed to the Times that investigators want to talk to the airman, described as a member of the Guard's intelligence wing.

President Joe Biden said earlier Thursday that U.S. officials were “getting close” to wrapping up their investigation into the leak. Asked by USA TODAY if he was concerned about the leak, Biden said, “I'm not concerned about the leak. I'm concerned that it happened. But there's nothing contemporaneous that I'm aware of that’s of great consequence.” Read more here.

'TOTALLY ILLEGAL': Biden blasts Russian arrest of Wall Street Journal reporter Evan Gershkovich

Latest developments:

►Norway said it is expelling 15 Russian diplomats suspected of spying while working at the Russian Embassy in Oslo. Foreign Minister Anniken Huitfeldt described the expelled Russians as “intelligence officers under diplomatic cover.”

►Foreign Minister Dmytro Kuleba said Thursday that his country remains firm in its demand that Russia withdraw its forces from Crimea, as well as from parts of Ukraine that Moscow illegally annexed since the invasion began in February 2012.

LEAK PROBE: US 'getting close' to wrapping up investigation into classified documents leak, Biden says

PENTAGON LEAK: Information won't impact Ukraine, experts say. But what is the 'political cost' to come?

Russia could make deal for WSJ journalist after trial

Russia may be willing to discuss a prisoner swap involving jailed Wall Street Journal reporter Evan Gershkovich after a court delivers its verdict on espionage charges, a top Russian diplomat said Thursday.

“We have a working channel that was used in the past to achieve concrete agreements, and these agreements were fulfilled,” Deputy Foreign Minister Sergei Ryabkov told state-run Tass news agency.

Not guilty verdicts are almost unheard of in Russian courts. U.S. basketball star Brittney Griner, who played in Russia during the WNBA off season, was convicted on drug charges and spent 10 months in prison before her December release in exchange for Russian arms dealer Viktor Bout.

Biden on Tuesday called Russia's detention of the American journalist "totally illegal,'' and the U.S. State Department elevated his case by formally categorizing him as wrongfully detained.

Gershkovich, 31, was detained by Russian authorities two weeks ago in the Ural Mountains city of Yekaterinburg. Russia alleged that Gershkovich "was acting on the U.S. orders to collect information about the activities of one of the enterprises of the Russian military industrial complex that constitutes a state secret."

The Wall Street Journal and the U.S. government have repeatedly denied that Gershkovich is a spy.

Russia names suspect in restaurant bombing that killed blogger

Russia's Federal Security Service on Thursday accused a Ukrainian man of organizing the St. Petersburg restaurant bombing that killed pro-Kremlin military blogger Vladlen Tatarsky and wounded dozens more. The agency said Yuriy Denysov, who it said was a working for Ukrainian security services, arrived in in Moscow from Kyiv, traveling through Latvia, in February. He rented an apartment next to Tatarsky and collected information about his "daily routine," the agency said.

Denysov also is accused of giving Darya Trepova the plaster statuette of Tatarsky stuffed with explosives that Trepova presented to Tatarsky moments before the blast. Trepova, being held in Russia, reportedly has denied knowing there was a bomb in the statuette.

The day after the explosion Denysov flew to Turkey. The FSB said it would put Denisov on the international wanted list.

Contributing: Joey Garrison, Michael Collins,Tom Vanden Brook, Maureen Groppe and Wyatte Grantham-Philips, USA TODAY; The Associated Press

This article originally appeared on USA TODAY: ukraine-russia-war-live-updates: Document leak mystery may be solved