President Trump has said he wants the FBI to conduct a "very comprehensive investigation" into sexual assault allegations against his Supreme Court nominee - but not a "witch hunt".
US media reports earlier suggested the White House wanted to restrict the inquiry into Judge Brett Kavanaugh.
Mr Trump said he had requested that the FBI be given free rein, but added: "I'd like it to go quickly."
Judge Kavanaugh's friend Mark Judge has been interviewed by agents.
A lawyer for Mr Judge - a childhood friend of Mr Kavanaugh - said on Monday that his client's interview "has not been completed".
Mr Judge's testimony is considered key to the investigation, as Professor Christine Blasey Ford says he was in the room when Brett Kavanaugh allegedly assaulted her at a house in 1982.
Mr Judge has not appeared before the Senate Judiciary Committee, but said in a statement: "I do not recall the party described in Dr Ford's letter."
On Monday, Senate Majority Leader Mitch McConnell said the upper chamber would vote this week on whether to confirm Judge Kavanaugh to the Supreme Court.
"The goal posts keep shifting," he said as he accused Democrats of attempting to derail the nomination. "But the goal hasn't moved an inch.
"The time for endless delay and obstruction has come to a close."
Mr McConnell did not specify when exactly the vote would be held, but it is expected to be Friday - the deadline for the FBI to finish its inquiry - or the following day.