WASHINGTON – A man President Donald Trump named as a member of his foreign policy team during the 2016 campaign began his two-week sentence on Monday for lying to the FBI about his Russian contacts.

George Papadopoulos, the first Trump campaign aide sentenced as a result of special counsel Robert Mueller's investigation into Russian election meddling, was ordered to report to the Federal Bureau of Prisons after his lawyers' last-ditch motions to delay his sentence were denied.

Papadopoulos arrived Monday at a minimum-security camp in Oxford, Wisconsin, the BOP confirmed to USA TODAY. There are currently 153 inmates at the camp, according to the agency's website.

U.S. District Court Judge Randolph Moss issued a 13-page ruling Sunday rejecting two motions filed by Papadopoulos' attorneys. Moss said Papadopoulos' time to file an appeal expired on Sept. 25 and that his hopes of having his plea deal voided by a case challenging Mueller's appointment were without merit.

The case before the U.S. Court of Appeals for the District of Columbia Circuit argues that Deputy Attorney General Rod Rosenstein did not have the constitutional authority to appoint Mueller after then-Attorney General Jeff Sessions recused himself from matters dealing with the Russia investigation. Papadopoulos' lawyers said it would be "unjust" for their client to go to prison only to see Mueller's investigation declared illegitimate after he served his time.

But Moss said those arguments had been available to Papadopoulos for more than a year. And he pointed out that two other judges had "issued thorough and carefully reasoned opinions rejecting the arguments that Papadopoulos now champions."

Moss said the "prospect that the D.C. Circuit will reach a contrary conclusion is remote."

The judge also said nothing in the Bail Reform Act cited by Papadopoulos' lawyers would justify suspending a sentence to await "an appeal brought by a different party in a different case."

Papadopoulos pleaded guilty last year to lying to the FBI about his Russian contacts while working for the Trump campaign in 2016. In September, he was sentenced to two weeks in prison, a year of supervised release, 200 hours of community service and a $9,500 fine.

Mueller's prosecutors had sought a six-month sentence for Papadopoulos, who asked the judge to give him probation. A conviction for lying to the FBI can carry a sentence of up to five years in prison.

According to Mueller, Papadopoulos "lied to the FBI regarding his interactions with a foreign professor whom he understood to have significant ties to the Russian government, as well as a female Russian national."

Papadopoulos identified that professor as Joseph Mifsud, who introduced him to the Russian woman he knew as Olga. Mifsud told Papadopoulos Olga was related to Russian President Vladimir Putin and Papadopoulos later identified her as "Putin's niece" in a campaign email.

When asked about his contacts with Mifsud and Olga, Papadopoulos falsely told the FBI agents that his meetings with them happened before he joined the Trump campaign.

Trump has downplayed Papadopoulos' role in the campaign. But in March 2016, he touted Papadopoulos as a part of his foreign policy team during a meeting with The Washington Post editorial board.

"He’s an energy and oil consultant," Trump said at the time. "Excellent guy."

According to Papadopoulos, he met with Trump, Sessions and other campaign officials at the Trump Hotel in Washington on March 31, 2016, and told them he could use his new connections to set up a meeting between Trump and Putin.

"While some in the room rebuffed George’s offer, Mr. Trump nodded with approval and deferred to Mr. Sessions who appeared to like the idea and stated that the campaign should look into it," Papadopoulos' lawyers wrote in a court filing.

Papadopoulos said his aim was to set up the meeting as part of Trump's stated goal of improving U.S. relations with Russia. But on April 26, 2016, Mifsud told Papadopoulos that the Russians had "thousands of emails" that contained "dirt" on Trump's opponent Hillary Clinton.

That was months before U.S. authorities discovered that Russian agents had hacked a heap of emails from Democratic officials.

Papadopoulos said he told Nikos Kotzias, the foreign minister for Greece, that the Russians had "dirt" on Clinton in May 2016. He made a similar boast that month while having drinks in London with Australian diplomat Alexander Downer.

The FBI began to investigate possible ties between Russia and the Trump campaign on July 31, 2016, after learning of Papadopoulos' claims.

In recent weeks, Papadopoulos has said publicly that he regrets pleading guilty and that he believes he was "framed." He says British and Australian intelligence agencies were "actively seeking to undermine Trump" and they were "spying" on him and the campaign.

Contributing: Brad Heath