Judge excoriates Trump ex-adviser Flynn, delays Russia probe sentencing

* Judge says Flynn 'arguably' sold out the United States

* Flynn still may face prison time, judge says

* 'We wish General Flynn well,' White House spokeswoman says (Adds judge imposes travel restrictions on Flynn, paragraph 12)

By Jan Wolfe and Ginger Gibson

WASHINGTON, Dec 18 (Reuters) - A U.S. judge fiercely criticized President Donald Trump's former national security adviser Michael Flynn on Tuesday for lying to FBI agents in a probe into Russian interference in the 2016 election, and delayed sentencing him until Flynn has finished helping prosecutors.

U.S. District Judge Emmet Sullivan told Flynn, a retired U.S. Army lieutenant general and former director of the Defense Intelligence Agency, that he had arguably betrayed his country. Sullivan also noted that Flynn had operated as an undeclared lobbyist for Turkey even as he worked on Trump's campaign team and prepared to be his White House national security adviser.

Flynn pleaded guilty to lying to FBI agents about his December 2016 conversations with Sergei Kislyak, then Russia's ambassador in Washington, about U.S. sanctions imposed on Moscow by the administration of Trump's Democratic predecessor Barack Obama. The conversations took place between Trump's November election victory and his inauguration in January 2017.

Special Counsel Robert Mueller, leading the investigation into possible collusion between Trump's campaign and Russia ahead of the election, had asked the judge not to sentence Flynn to prison because he had already provided "substantial" cooperation over the course of many interviews.

Lying to the FBI carries a statutory maximum sentence of five years in prison. Flynn's plea agreement stated that he was eligible for a sentence of between zero and six months.

Sullivan sternly told Flynn his actions were abhorrent, noting that Flynn had also lied to senior White House officials, who in turn misled the public. The judge said he had read additional facts about Flynn's behavior that have not been made public.

At one point, Sullivan asked prosecutors if Flynn could have been charged with treason, although the judge later said he had not been suggesting such a charge was warranted.

"Arguably, you sold your country out," Sullivan told Flynn. "I'm not hiding my disgust, my disdain for this criminal offense."

Flynn, dressed in a suit and tie, showed little emotion throughout the hearing, and spoke calmly when he confirmed his guilty plea and answered questions from the judge.

Sullivan appeared ready to sentence Flynn to prison but then gave him the option of a delay in his sentencing so he could fully cooperate with any pending investigations and bolster his case for leniency. The judge told Flynn he could not promise that he would not eventually sentence him to serve prison time.