A United States Army soldier was criminally charged Monday after sharing tips about building homemade explosives, and talking about bombing a major American news network, attacking leftist groups and traveling to Ukraine to fight with a far-right paramilitary group , authorities said.

Jarrett William Smith, 24, a private first class stationed in Fort Riley, Kansas, was charged with one count of distributing information related to explosives and weapons of mass destruction, the Department of Justice said.

He faces a maximum possible sentence of 20 years in prison if convicted.

A criminal complaint filed in U.S. District Court in Kansas against Smith, who joined the Army in June 2017, details interactions he had on social media with other users in which he discussed how to build improvised explosive devices.

Smith allegedly told an FBI agent shortly before his arrest Saturday that he shared that knowledge "to cause 'chaos,' " and that "it doesn't affect him" if that chaos leads to deaths of other people.

In a chat on the Telegram messaging app last Friday, Smith allegedly suggested that former U.S. Rep. Beto O'Rourke — who currently is seeking the Democratic nomination for president — could be a target for a bomb that an FBI undercover employee told him he wanted to use to kill a politician in Texas.

O'Rourke's campaign spokeswoman, in a statement, said, "We're grateful to the FBI for their diligence in handling this case and for their work to keep our country safe in the face of domestic terror threats."

"We take any threat like this very seriously, and our team is in direct contact with the FBI regarding this case. This isn't about any one person or one campaign, and we won't let this scare us or cause us to back down in fighting for what's right," the spokeswoman said.