Senator Mark Warner, the ranking Democrat on the Senate Intelligence Committee, said Sunday that intelligence community leaders have expressed serious concerns about President Trump's selection of Bill Pulte as acting Director of National Intelligence.

Speaking on CBS's "Face the Nation with Margaret Brennan," Warner said "heads of our intelligence community" told him they are "terrified of showing" information to Pulte, who is set to take over the role when Tulsi Gabbard steps down from the position.

Trump named Pulte as the temporary intelligence chief while Gabbard transitions out of the DNI role. The acting appointment would give Pulte access to the nation's most sensitive intelligence information and oversight of the country's intelligence agencies.

In response to the nomination, Democrats are blocking the reauthorization of a key surveillance authority as a form of protest against Pulte's appointment. Warner indicated this legislative delay is directly tied to concerns about Pulte assuming the intelligence role.

The Director of National Intelligence serves as the head of the U.S. Intelligence Community and principal intelligence advisor to the President, coordinating intelligence activities across multiple agencies including the CIA, FBI, and NSA.