Robert Mueller has asked the White House for phone records related to the statement drafted by the White House about a meeting Donald Trump Jr. attended with a Russian lawyer at Trump Tower last year as part of the federal investigation into Russian meddling in the 2016 election, according to a report.

In addition to the phone records, sources told Politico that Mueller also requested emails and documents from the White House related to a May 3 White House press briefing, during which then-White House press secretary Sean Spicer told reporters President Trump had confidence in former FBI Director James Comey.

Trump ultimately fired Comey on May 9 and initially said his decision was based on the recommendation of Deputy Attorney General Rod Rosenstein. But in an interview with NBC News on May 11, the president said he made the decision to fire Comey before receiving Rosenstein's recommendation.

White House officials said Trump ultimatley decided to terminate Comey after Spicer's May 3 press briefing while the president was at his golf club in Bedminster, N.J., according to Politico.

In addition to seeking phone records related to the statement on the Trump Tower meeting and documents pertaining to Spicer's briefing, Mueller has asked for documents connected to former National Security Adviser Michael Flynn and his contacts with Russian officials, and documents related to former Trump campaign chairman Paul Manafort.

Flynn was fired in February after it was revealed he lied to Vice President Mike Pence about his communications with Russian officials. Former Deputy Attorney General Sally Yates told a Senate Judiciary subcommittee in May she met with White House counsel Don McGahn to warn him she had information that Flynn misled Pence.

A White House official told Politico it's unlikely there are many documents referencing Manafort since he left his post with the campaign several months before the election.

Mueller's request for phone records related to the statement drafted about Trump Jr.'s meeting at Trump Tower comes after it was revealed the special counsel's team is interested in interviewing six former and current administration officials about the statement and other events in the White House.

The Washington Post reported earlier this month Mueller wants to speak with White House communications director Hope Hicks and Office of American Innovation spokesman Josh Raffel, both of whom were part of internal discussions about the White House's response.

The statement was drafted from Air Force One during the president's return trip to the U.S. from the G-20 summit in Europe, and as White House officials hashed out the response to revelations about Trump Jr.'s meeting, calls were placed to and from the plane, Washington and New York, Politico reported.

It was reported Trump Jr. met with Russian lawyer Natalia Veselnitskaya at Trump Tower in June 2016 after he was promised damaging information on Hillary Clinton.

Part of Mueller's investigation into Russian meddling in the 2016 election is reportedly focused on whether the president obstructed justice when he fired Comey, as well as possible collusion between Trump campaign officials and Russia.