President Trump was reportedly angry after the FBI released a public statement expressing “grave concerns” about the accuracy of a controversial memo that details alleged abuses of a government surveillance program.

Sources told CNN the president was upset about the FBI’s release regarding the four-page memo compiled by House Intelligence Committee Chairman Devin Nunes, R-Calif., and Republican staff.

The FBI’s statement came after the president was heard telling a Republican lawmaker Tuesday night he would “100 percent” release the memo.

The document details alleged abuses by FBI and Justice Department officials of a government surveillance program used to obtain a warrant to spy on Carter Page, an adviser to the Trump campaign.

The House Intelligence Committee voted along party lines Monday to allow the memo to be released to the public. The vote triggered a five-day deadline for Trump to decide whether to allow the memo to be made public, and a decision from the president is expected Thursday.

Trump has told those close to him he thinks the memo will help cast doubt on the Justice Department’s investigation into Russian meddling in the 2016 election and possible collusion between the Trump campaign and Moscow, CNN reported.

The president has also said he thinks the memo will demonstrate the political bias that exists within the upper echelons of the FBI.

Trump is reportedly frustrated with Deputy Attorney General Rod Rosenstein for his handling of the Russia probe. Rosenstein, who is reportedly named in the memo, approved the application to continue surveillance of Page, the New York Times reported.