President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE on Sunday said he’ll ask the Department of Justice (DOJ) to investigate whether the FBI surveilled his campaign.

“I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration!” Trump tweeted.

I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration! — Donald J. Trump (@realDonaldTrump) May 20, 2018

Not long afterward, the DOJ announced it had asked its inspector general to expand its probe into alleged surveillance abuses to encompass the most recent claims.

“If anyone did infiltrate or surveil participants in a presidential campaign for inappropriate purposes, we need to know about it and take appropriate action," Deputy Attorney General Rod Rosenstein said in a statement on Sunday afternoon.

Trump has spent the last few days sounding the alarm on Twitter about claims that an FBI informant was embedded within his campaign. He has alleged, without evidence, that the FBI sought to spy on his campaign for political purposes, which Trump argued would be a scandal "bigger than Watergate."

ADVERTISEMENT

The New York Times reported Friday that an FBI informant met with two former Trump campaign advisers, George PapadopoulosGeorge Demetrios PapadopoulosTale of two FBI cases: Clinton got warned, Trump got investigated Trump says he would consider pardons for those implicated in Mueller investigation New FBI document confirms the Trump campaign was investigated without justification MORE and Carter Page, after they'd received information that those two had contacts with Russia.

Trump's calls for an investigation into the matter come as House Republicans have pushed for access to documents that reveal the identity of the informant who gave investigators information about possible ties between the Trump campaign and Russia.

The DOJ denied a request earlier this month from House Intelligence Committee Chairman Devin Nunes Devin Gerald NunesSunday shows preview: Justice Ginsburg dies, sparking partisan battle over vacancy before election Sunday shows preview: With less than two months to go, race for the White House heats up Sunday shows preview: Republicans gear up for national convention, USPS debate continues in Washington MORE (R-Calif.) for details related to the source. The DOJ said that releasing such information would put lives at risk and endanger national security.

Despite those warnings, Trump has joined in the calls for the source to be revealed.

Democrats have also warned that doing so would jeopardize the source and national security, and could pose a legal risk. They have suggested claims the FBI spied on Trump's campaign are part of an effort to undermine special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE's probe into Russian meddling in the 2016 election.

Trump has long blasted Mueller's probe as a "witch hunt" and a "hoax."

Four former Trump associates have pleaded guilty or been indicted as part of the investigation thus far.

Updated: 7 p.m.