WASHINGTON – President Donald Trump is eager to see the release of secret documents related to the probe of Russian interference in the 2016 U.S. election, but FBI text messages and other materials may not be made public anytime soon.

Intelligence officials are reviewing the documents to remove sensitive information following Trump's declassification order this week. The president has said he believes the documents will bolster his argument that investigators in the Russia probe are biased against him.

There is no way to tell how long the review process will take, said officials with the White House, Justice Department and the office of the Director of National Intelligence.

Meanwhile, Democrats who sit on congressional intelligence committees said Trump is trying to undermine special counsel Robert Mueller's investigation. They want a briefing from the intelligence community before any documents are released.

Sen. Mark Warner, D-Va., top Democrat on the Senate Intelligence Committee, told reporters that presidents have the right to declassify documents, but Trump's order comes "in the midst of an investigation of his own campaign."

Said Warner: "This is an attempt to stifle the investigation."

While Trump says he believes the documents will back up his claims of bias, some lawmakers said they may underscore the justification for the Russia probe. "Be careful what you wish for," Warner said.

The dispute, which could play out over weeks, revolves around Trump's long-running attacks on Mueller, the Justice Department, and the FBI over the Russia investigation.

Mueller's team is investigating, among other things, whether there was any coordination between anyone from his campaign and Russia and also whether there were any efforts by the president or his aides to try to obstruct the investigation.

Trump has called the Mueller probe a "hoax" and a "witch hunt" and has denied any collusion between his campaign and Russia.

The documents Trump wants released include parts of the application to monitor the communications of Carter Page, a former aide to the president's campaign. It would include FBI reports of interviews prepared in connection with that application.

Trump has suggested that FBI officials improperly obtained the warrant to monitor Page. The president and his Republican allies in the House argue that the warrant was based in part on information compiled in a dossier from ex-British spy Christopher Steele, retained by the consulting firm Fusion GPS.

Trump also ordered release of interviews conducted by Bruce Ohr, a Justice Department official whose wife has done work for Fusion GPS.

While a law firm representing the Democratic National Committee and Democrat Hillary Clinton's campaign hired Fusion GPS when it used Steele, the firm also did research on Trump for Republican critics of the then-New York businessman.

Trump has ordered the release of any text messages on the Russia investigation by Ohr and four other now-former FBI officials: James Comey, Andrew McCabe, Peter Strzok and Lisa Page.

Trump's dismissal of Comey, the longtime FBI director, led to the appointment of Mueller as special counsel. It is also the focus of an investigation into whether Trump sought to obstruct justice in the Russia investigation, something the president has denied.

Previous text messages that have been released reflected criticism of Trump by FBI officials Strzok and Page. The two officials, who were having an affair at the time, spoke of a strategy to pursue the Russia allegations. When Page texted that Trump is "not ever going to become president, right? Right?!" Strzok responded: "No. No he's not. We'll stop it."

During a congressional hearing in July, Strzok said he and Page were simply expressing personal opinions, and "at no time in any of these texts did those personal beliefs ever enter into the realm of any action I took."

In a statement, the Justice Department said that Trump's order triggered "a declassification review process" in which intelligence agencies and the White House counsel's office "seek to ensure the safety of America's national security interests."

It did not say when the review might be completed, or whether documents might be released gradually.

“As requested by the White House, the ODNI is working expeditiously with our interagency partners to conduct a declassification review of the documents the president has identified for declassification," said Kellie Wade, a spokeswoman at the ODNI.

Trump is seeking the released of FBI texts without redactions, and that could further delay the process.

In an interview with Hill.TV, Trump said he ordered the declassification to expose the Russia investigation as a "hoax." He also described the FBI as "corrupt."

He also told Hill.TV he has not reviewed the documents he wants declassified.

More:British spy Steele told DOJ lawyer Ohr Russia had ‘Trump over a barrel,' report says

More:President Trump, allies dismiss revelations in new court documents tied to Russia probe

Some lawmakers said the warrant to monitor Page was justified based on evidence of frequent contacts between Russians and people involved in the Trump campaign.

Sen. Richard Burr, R-N.C., chairman of the Senate Intelligence Committee, told CNN in July the judges had “sound reasons” for issuing the Page surveillance warrant.

In a letter to the leaders of the FBI, the Justice Department and the ODNI, Democrats said Trump is trying to "manipulate" classified information "to undermine the legitimacy and credibility of the Special Counsel’s investigation."

The letter was signed by House Democratic leader Nancy Pelosi, D-Calif., and Sen. Chuck Schumer, D-N.Y., as well as Warner and Rep. Adam Schiff, D-Calif., top Democrat on the House Intelligence Committee.

"Any decision by your offices to share this material with the President or his lawyers will violate longstanding Department of Justice policies, as well as assurances you have provided to us," the letter said.