President Donald Trump smiles in the East Room of the White House in Washington, D.C. on September 12, 2018.

President Donald Trump on Monday declassified a trove of documents related to the early days of the FBI's Russia investigation, including portions of a secret surveillance warrant and former FBI Director James Comey's text messages.

Trump made the extraordinary move in response to calls from his allies in Congress who say they believe the Russia investigation was tainted by anti-Trump bias within the ranks of the FBI and Justice Department. It also came as Trump continued his efforts to undermine special counsel Robert Mueller's probe in the wake of the guilty plea of his former campaign chairman, Paul Manafort, and amid the ongoing grand jury investigation into a longtime associate, Roger Stone.

Trump's decision will result in the release of text messages and documents involving several top Justice Department and FBI officials who Trump has repeatedly attacked over the last year.

"When the President issues such an order, it triggers a declassification review process that is conducted by various agencies within the intelligence community, in conjunction with the White House Counsel, to seek to ensure the safety of America's national security interests," A DOJ spokesperson told CNBC.

"The Department and the Federal Bureau of Investigation are already working with the Director of National Intelligence to comply with the President's order," the spokesperson said.

White House press secretary Sarah Huckabee Sanders announced Trump's decision in a written statement, saying the president had directed the Office of the Director of National Intelligence and the Justice Department to declassify the documents "at the request of a number of committees of Congress, and for reasons of transparency."

According to the statement, Trump declassified about 20 pages of the warrant obtained under the Foreign Intelligence Surveillance Act to monitor the communications of former Trump campaign adviser Carter Page and FBI interviews conducted to secure that warrant.

He also is declassifying all FBI reports documenting interviews with senior Justice Department official Bruce Ohr, who was in contact with ex-British spy Christopher Steele. Steele was a longtime FBI informant whose Democratic-funded research into Trump ties to Russia was compiled into a dossier that has become a partisan lightning rod since its publication in January 2017.

According to Sanders' statement, Trump also directed the Justice Department to publicly release in full the text messages of Comey, Ohr, former FBI Director Andrew McCabe, former FBI lawyer Lisa Page and former FBI special agent Peter Strzok.