Top U.S. intelligence officials insisted Wednesday that they have never faced pressure to shape intelligence assessments to fit a political goal, amid questions from Democrats about whether President Trump pushed officials to drop a probe into Russia's influence on the election.

Sen. Mark Warner, D-Va., the top Democrat on the Senate Intelligence Committee, used a Wednesday morning hearing to ask two top officials whether they have felt political pressure in any way, but both denied it.

"In the three-plus years that I have been the director of the National Security Agency, to the best of my recollection, I have never been directed to do anything I believe to be illegal, immoral, unethical or inappropriate," said National Security Agency Director Michael Rogers. "And to the best of my recollection, during that same period of service, I do not recall ever feeling pressured to do so."

Director of National Intelligence Dan Coats gave a similar answer.

"I've never felt pressure to intervene or interfere in any way, with shaping intelligence in a political way or in relation to the ongoing investigation," he said.

Democrats have been hoping for confirmation of press reports that President Trump may have pressured top intelligence officials, including Coats, to ask former FBI Director Comey to "back off" an investigation of national security adviser Mike Flynn. They'll get another chance on Thursday, when Comey testifies before the committee.

But Rogers and Coats declined to go much further. When asked more specifically if Trump ever asked him to help dismiss the Russia probe, Rogers said he was "not going to discuss specifics of conversations" with the president.

Coats answered similar questions by saying he was not able to say anything more in an open session.