"Going forward all questions on these matters will be referred to outside counsel Marc Kasowitz", White House spokesman Sean Spicer told reporters when asked about a media report on what Comey planned to say in congressional testimony.
Nunes, who was a member of Trump's transition team, had raised the topic of unmasking after the committee heard testimony March 20 from then Federal Bureau of Investigation director James Comey that the FBI was investigating possible collusion between the Trump campaign and Russian Federation during last year's election campaign.
Committee Republicans have been demanding answers on how the names of President Trump's campaign officials were exposed in classified reports that resulted from interceptions of various communications.
Exactly 40 percent of respondents said Trump's counselor Kellyanne Conway, who faced heat for her "Bowling Green Massacre" remarks, also damages the President's administration compared to the 28 percent who said she is helpful.
His last day on the job has not yet been determined.
White House chief of staff Reince Priebus thanked Mr. Dubke in a statement and said Mr. Dubke had "offered to remain onboard until a transition is concluded".
Subpoenas were also approved by the committee for documents possessed by the Flynn Intel Group LLC and Michael D. Cohen & Associates PC.
"I can not think of any compelling patriotic reason why any American, let alone someone working for the White House, would create secret back-channel communications with the Russians", said former Central Intelligence Agency operative Emily Brandwin. The official said Kushner was eager to share what he knows with Congress and other investigators.More news: R&B singer Brandy hospitalized after apparently losing consciousness on flight
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"I want to know if anyone in the Trump camp conspired with the Russians in their interference in our election".
He said that he believes Trump's presidential performance "has been quite poor" so far, but he added that Trump has grounds to say that the media is biased against him.
The Office of the White House Press Secretary said that the president has always been consistent about his intention to move the embassy to Jerusalem, and it was only a question of timing to go ahead with it.
"There are so many "facts" in the public domain now that many people are connecting them in a way that has them concluding the Trump campaign must have been guilty of conspiring with the Russians in a way that would be a violation of the law. This action would have been taken without the minority's (Democrats') agreement", said a senior committee aide, speaking on condition of anonymity. Other supporters have pointed to decades of precedent for back-channel communications - from Henry Kissinger and China to Barack Obama and Cuba. "The proper line (from Kushner was) simply (to say), 'Happy to hear what you have to say to us, but we have one president at a time.' I was on (the Mitt Romney) team (in 2012) and that was our plan".
Nunes' problems began after Trump had tweeted the wiretapping allegations.
The discussions included the US sanctions against Russian Federation.