A committee of the U.S. House of Representatives says it has sent document requests to 81 entities and individuals as part of a new investigation into alleged obstruction of justice and other abuses by President Donald Trump and his associates.
Judiciary Committee Chairman Jerrold Nadler said on March 4 that it was the "obligation" of Congress to "provide a check on abuses of power" by the White House.
The White House said that it had received the Democrat-led House committee's letter.
"The counsel's office and relevant White House officials will review it and respond at the appropriate time," spokeswoman Sarah Sanders said.
Asked by a journalist whether he will cooperate with the probe into his White House, campaign, and businesses, Trump, a Republican, said, "I cooperate all the time with everybody."
"You know, the beautiful thing, no collusion. It's all a hoax," he added.
The move comes as Special Counsel Robert Mueller, who is leading an investigation into Russia's alleged interference in the 2016 U.S. presidential election and possible collusion between Trump's campaign and Moscow, is expected to deliver his findings to the attorney general within weeks.
Trump rejects any charges of collusion between his campaign and Moscow, and the Kremlin denies meddling in the U.S. election.