Washington (CNN) Investigators for the special counsel investigating questions of Russian interference in the 2016 election will soon speak to senior intelligence officials, a source familiar with the matter tells CNN.

Special counsel Robert Mueller's investigators have asked for information and will talk to Director of National Intelligence Dan Coats and National Security Agency Director Adm. Mike Rogers, according to a source familiar with the matter.

Investigators have also sought information from recently retired NSA Deputy Director Richard Ledgett, according to the source. Ledgett wrote a memo, according to the source, documenting a conversation in which President Donald Trump allegedly urged Rogers to help get the FBI to lift the cloud of the Russia investigation.

Law enforcement sources tell CNN that the special counsel is gathering information and considering whether there is evidence to launch a full-scale obstruction investigation.

The interviews are some of the first indications of the efforts of Mueller's newly assembled team. Ultimately, it would be up to Mueller to decide whether there is enough evidence to recommend pursuing charges on any part of the investigation.

Any finding that could arise against the President would have another hurdle -- a longstanding Justice Department stance against indicting a sitting president. However, a finding of wrongdoing would likely be left to Congress to consider whether it warranted criminal impeachment.

The source who spoke to CNN would not say that the investigators were talking to the senior intelligence officials specifically about conversations they had with the President about the investigation, or other aspects of the investigation which also includes examining Russian meddling in the election and possible coordination with associates of Trump.

A spokesman for the office of the special counsel declined comment. A spokesman for the DNI also declined to comment to CNN. The NSA said in a statement: "NSA will fully cooperate with the special counsel. We are not in a position to comment further."

Trump, however, referred to the Post's reporting as a "phony story" in a Thursday morning tweet.

"They made up a phony collusion with the Russians story, found zero proof, so now they go for obstruction of justice on the phony story. Nice," the President tweeted

At a hearing last week, both Coats and Rogers said they were not pressured by the Trump administration.

"I have never been directed to do anything I believe to be illegal, immoral, unethical or inappropriate," Rogers said. "And to the best of my recollection, during that same period of service, I do not recall ever feeling pressured to do so."

Mueller is already in possession of the memos written by the former FBI director, who documented each of his interactions with the President.

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Mueller was on Capitol Hill Tuesday discussing the probe with Senate Intelligence Chairman Richard Burr of North Carolina and Virginia Sen. Mark Warner, who is the committee's top Democrat.

After the meeting with Mueller, Warner was asked by CNN's Manu Raju whether the committee is looking into obstruction of justice or if that was part of the special counsel investigation. Warner responded that "the criminal piece of the investigation will be handled by the special counsel, but if we find facts we can turn this over to the special counsel" and "report them" to Mueller's office.

Mark Corallo, a spokesman for Trump's outside attorney Marc Kasowitz, said in a statement to CNN: "The FBI leak of information regarding the President is outrageous, inexcusable and illegal."