What you need to know about Trump campaign adviser George Papadopoulos, who pleaded guilty to lying to FBI

WH says he did nothing in an "official capacity on behalf of the campaign.”

Papadopoulos admitted to making false statements and omitting information during an interview with the FBI Jan. 27, 2017, according to the federal statement of the offense that was unsealed by special counsel Robert Mueller's team.

Papadopoulos' attorneys Thomas M. Breen and Robert W. Stanley said in a statement, “It is in the best interest of our client, George Papadopoulos, that we refrain from commenting on George’s case.”

"We will have the opportunity to comment on George’s involvement when called upon by the Court at a later date. We look forward to telling all of the details of George’s story at that time."

Papadopoulos, while living in London, learned he was going to be an adviser to the campaign in early March of 2016, according to the statement of offense released today.

Papadopoulos was most recently serving as an independent oil, gas and policy consultant for the International Presidential Business Advisory Council, according to information from his LinkedIn account.

White House press secretary Sarah Sanders said during today’s press briefing that Papadopoulos was only a volunteer on the campaign and did not hold a paid position.

“It was extremely limited,” she said of his role.

Sanders added: "No activity was ever done in an official capacity on behalf of the campaign.”

As for his involvement on the International Presidential Business Advisory Council, Papadopoulos was a "volunteer member of an advisory counsel that literally met one time," Sanders said.

Trump, during a visit to the Washington Post headquarters March 21, revealed the names of his foreign policy team and included Papadopoulos, whom he described as an "energy and oil consultant, excellent guy."

Asked today about Trump's March comments that Papadopoulos is an "excellent guy," Sanders said Trump was being nothing more than "complimentary on behalf of the campaign."

“Our records indicate that Mr. Papadopoulos started at Hudson Institute as an unpaid intern in 2011 and subsequently provided research assistance on a contractual basis to one of our senior fellows," the Hudson Institute said in a statement to ABC News.

"Mr. Papadopoulos was never a salaried employee of Hudson Institute, we have had no relationship with him since 2014, and it would be inappropriate for us to comment on legal proceedings of which we have no knowledge and to which we are not a party.”

Here's the federal statement of the offense against Papadopoulos.

ABC News' MaryAlice Parks and Mike Levine contributed to this report.