Special counsel Robert Mueller has asked a judge for a September sentencing for former Trump campaign adviser George Papadopoulos.

Mueller's prosecutors and defense attorneys in a Friday court filing asked U.S. District Court Judge Randy Moss to set Papadopoulos's sentencing for Sept. 7 or for a date in October barring his availability in September, Politico reported.

Papadopoulos, who served as a foreign policy adviser for the Trump campaign, pleaded guilty last year to making false statements to FBI agents about his contacts with pro-Russia sources during the 2016 presidential election. He is one of three Trump associates - along with businessman Richard Gates and former national security adviser Michael Flynn - to plead guilty to making false statements.

The former Trump campaign aide was arrested last July and has been out on bond since pleading guilty.

President Trump sought to distance himself from the aide after he pleaded guilty, describing Papadopoulos as a low-level volunteer with few real responsibilities. Papadopoulos and his fiancee have pushed back on that assertion.

"Few people knew the young, low-level volunteer named George, who has already proven to be a liar. Check the DEMS!" Trump tweeted in October.

The New York Times reported last year that Papadopoulos was key in prompting Mueller's Russia investigation after he bragged to an Australian diplomat that the Russians had damaging information on Democratic presidential candidate Hillary Clinton. The incident occurred before the Democratic National Committee was hacked by the Kremlin in 2016.

Australian government officials tipped off the FBI to Papadopoulos's remarks, sparking the now yearlong special counsel probe into possible ties between the Trump campaign and Russia.