House Intel delays Hope Hicks interview in Russia investigation

The surprise move came after Steve Bannon refused to answer scores of questions about topics during the transition and his time as President Donald Trump's chief strategist, with Bannon's attorney saying he had been instructed by the White House not to answer those questions over concerns that it could breach executive privilege.

But Hicks' appearance was anticipated given her close ties to Trump, which predate the campaign and the central role she has played through the election season and in the White House.

The committee made the decision to delay Hicks' appearance -- which was slated for Friday -- out of concern she would pull a similar tactic, giving investigators time to sort out with the White House what she could and could not discuss, one of the sources said. She is still expected to speak with the panel at a later date.

The White House and an attorney for Hicks did not respond to request for comment.

On Wednesday, White House press secretary Sarah Sanders said the White House was cooperating with the congressional investigations.

"We've been fully cooperative with the ongoing investigations, and we're going to continue to do so," Sanders said. "And we encourage the committees to work with us to find the appropriate accommodation in order to ensure Congress obtains all the information that they're looking for. But there's a process that this works through."