A top White House official declined in several interviews over the weekend to defend national security adviser Michael Flynn, amid controversy over his alleged contacts with Russia.
Flynn reportedly discussed sanctions with Russian officials in the weeks before Trump took office.
He initially denied any contact but later said he could not remember.
Such discussions could violate laws against private citizens engaging in foreign policy.
Stephen Miller, President Donald Trump’s top policy adviser, avoided the issue when asked in a number of interviews.
Miller said it was not his place to comment on the “sensitive matter” concerning Flynn, who was an early supporter of r Trump but whose position in the administration is thought to be under scrutiny.
Flynn spoke with Russia’s ambassador, Sergei Kislyak, by phone in December.
He denied discussing US sanctions imposed over Russia’s annexation of Crimea, but nine current and former officials later told the Washington Post that the issue had been discussed.
Flynn’s spokesman subsequently told reporters that he couldn’t be certain and he had not discussed sanctions.
Trump, who spent the weekend at his club in Florida, Mar-a-Lago, has not commented on the controversy.
Vice-President Mike Pence is also yet to comment on the controversy. Pence previously denied that Flynn had any contact with Russian officials, and the two men spoke twice on Friday, according to the Associated Press.
Trump is said to be troubled by the situation and uncertain as to whether he will ask Flynn to step down, the AP reported, citing administration officials.
Several other White House officials, as well as Miller, declined over the weekend to comment on the situation.