NEW YORK — The FBI said Monday it is investigating whether President Donald Trump and his campaign colluded with Russian officials to help him win the 2016 presidential election.

The bureau’s announcement comes just days after a congressional committee called on Trump to testify before a House committee investigating possible ties between the president and Russia.

The FBI’s announcement did not name Trump.

The president’s office did not immediately respond to a request for comment.

In addition to the new probe, Trump’s former national security adviser Michael Flynn pleaded guilty in March to lying to the FBI about his contacts with Russian Ambassador Sergey Kislyak.

Trump fired Flynn last month amid questions about whether he knew of the conversations before Trump took office.

On Monday, White House press secretary Sarah Sanders said Flynn’s plea “is part of a larger investigation.”

The FBI has opened a criminal investigation into Flynn’s interactions with Kislyak and the Russian ambassador’s representatives, the agency said in a statement Monday.

Sanders did not directly answer questions about why Flynn had not been indicted.

The statement did not specifically name Trump, but the White House did say that Flynn’s actions violated the emoluments clause of the U.S. Constitution.

Trump has said he believes the clause forbids him from accepting payments from foreign governments or governments that have a conflict of interest with the U,S.

government.

Flynn’s lawyer did not respond to requests for comment on Monday.

The House Intelligence Committee, which is investigating the Russia investigation, said it had not seen the new FBI statement.

House Intelligence Chairman Devin Nunes, R-Calif., has said Flynn should testify before the committee before the end of the year.

The committee has asked the Justice Department to conduct an independent review of Flynn’s communications with Kislyak.

Flynn has denied any wrongdoing and the Justice Justice Department has not responded to multiple requests for information on Flynn.