Angus King. Kevin Lamarque/Getty Images Sen. Angus King of Maine grilled two of the top US intelligence officials Wednesday on their refusal to answer questions about their conversations with President Donald Trump during a committee hearing.

King pressed the men a day after The Washington Post reported that Trump tried to get both of them to intervene in the FBI's Russia investigation.

Trump last month fired FBI Director James Comey, who oversaw the bureau's investigation into Russian election meddling, after the Post's reported efforts to get Coats and Rogers to intervene in the investigation. The Post reported that both Coats and Rogers refused to do so.

In the Wednesday hearing, National Security Agency Director Mike Rogers refused to discuss specifics about his conversations with Trump. He said he had never felt "pressured" to alter the course of an investigation, adding that no president had ever "directed" him to do any unethical or "illegal" acts.

Dan Coats, the director of national intelligence, echoed Rogers in his initial response, saying he "never felt pressured" to intervene in an ongoing investigation.

King opened his line of questioning by asking if Rogers discussed his testimony before the committee with the White House ahead of time. Rogers said he did, asking if the White House "intended to invoke executive privileges associated with any interactions between" himself and Trump. But Rogers said he "didn't get a definitive answer" on whether the president would invoke executive privilege, making any of the conversations off-limits to be discussed before the committee.

"So then I'll ask both of you the same question," King said. "Why are you not answering these questions? Is there an invocation by the president of the United States of executive privilege? Is there or not?"

"Not that I'm aware of," Rogers replied.

"Then why are you not answering our questions?" King snapped back.

Rogers said he was not answering questions on the content of his conversations with Trump "because I feel it is inappropriate."

"What you feel isn't relevant, admiral," King said. "What you feel isn't the answer."

"Is there an invocation of executive privilege?" he asked again. "If there is, let's know about it. If there isn't, answer the questions."

Rogers refused to expand, standing by his initial comments in the hearing.

"I'm not interested in repeating myself sir," Rogers said. "And I don't mean that in a contentious way."

"Well, I do mean it in a contentious way," King fired back. "I don't understand why you're not answering our questions."

Mike Rogers, right, seated next to Dan Coats. Kevin Lamarque/Reuters

Rogers called the conversations "classified" and said it was inappropriate to discuss them "in an open forum."

"What is classified about a conversation involving whether or not you should intervene in the FBI investigation," King asked, to which Rogers reiterated that he was standing by his earlier remarks.

The Maine senator, an independent who caucuses with the Democrats, then moved on to Coats.

"What's your basis for your refusal to answer these questions today?" he asked.

But Coats too was standing by his initial comments and saying he did not believe it was "appropriate" for him to speak on those conversations during the open hearing.

"What's the basis?" King asked. "I'm not satisfied with 'I do not believe it is appropriate' or 'I do not want to answer.' I want to understand the legal basis. You swore that oath to tell us the truth, the whole truth, and nothing but the truth. And today you are refusing to do so. What is the legal basis for your refusal to testify to this committee?"

Coats said he was "not sure I have a legal basis."

"But I am more than willing to sit before this committee in its investigative process in closed session and answer your questions," he continued.

Both Coats and Rogers agreed that the "appropriate" thing was to discuss the matter in the closed session, which was set to take place later Wednesday afternoon. But both also said they still need to consult the White House on whether executive privilege will be invoked.

In his concluding remarks, King said Coats' and Rogers' earlier insistence that they had not been pressured by Trump "waived executive privilege by in effect testifying as to something that didn't happen."

"And I believe you opened the door to these questions," King said. "It is in my belief that you are inappropriately refusing to answer these questions."