WASHINGTON — A member of the president's outside legal team said Sunday that Donald Trump is not under investigation, days after Trump tweeted about being the target of a "witch hunt."

Appearing on a series of morning news programs, attorney Jay Sekulow said that a Friday tweet from Trump was specifically directed at a story in The Washington Post about the expanding probe into Russia's election meddling.

"The president is not under investigation by the special counsel," said Sekulow. "The tweet from the president was a response to the five anonymous sources that were purportedly leaking information to The Washington Post about a potential investigation of the president."

The Post reported last week that Robert Mueller — the special counsel appointed to investigate Russian involvement in the 2016 presidential election — was looking into whether Trump obstructed justice. Mueller was appointed by Deputy Attorney General Rod Rosenstein and has expansive powers to probe any matters that develop from his initial investigation.

The president wrote on Twitter Friday: "I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt."

The message apparently referred to Rosenstein, whose role leading the federal investigation has become increasingly complicated. The White House used a memo he wrote to justify Trump's decision to fire FBI Director James Comey, but Trump's firing of Comey may now be part of the probe.

The president has denied that he has any nefarious ties to Russia and has also disputed that he's attempted to block the investigation into his campaign's possible role in Russia's election-related hacking. Trump advisers describe the president as increasingly angry over the investigation, yelling at television sets carrying coverage and insisting he is the target of a conspiracy.

The president has directed some of his frustration at Rosenstein and Mueller. But Sen. Marco Rubio said Sunday that he does not expect Trump to seek to fire them.

"I don't believe it's going to happen," said Rubio on CNN's "State of the Union." ''The best thing that could happen for the president, and the country, is a full and credible investigation. I really, truly believe that. If we want to put all this behind us, let's find out what happened, let's put it out there, and let's not undermine the credibility of the investigation."

Trump is under pressure to reveal whether he has any tape recordings of private conversations with Comey. Rep. Adam Schiff, the top Democrat on the House intelligence committee, said on ABC's "This Week" that the panel is looking forward to getting a response from the White House on whether recordings exist.

The president suggested on Twitter that he may have taped conversations. Schiff said he wants the White House to acknowledge the tapes or make clear there are no tapes and "it was an idle threat."

The panel sent a bipartisan letter this month to White House counsel Don McGahn seeking an answer by this Friday. The committee also sent a letter to Comey asking for any notes or memos.

Schiff said if the panel can't get an answer then he believes a subpoena will be needed.

While aides have advised Trump to stay off Twitter, the president continued to weigh in on the widening legal investigations Sunday.

In a two-part tweet posted before 7 a.m., Trump wrote: "The MAKE AMERICA GREAT AGAIN agenda is doing very well despite the distraction of the Witch Hunt."

Trump adviser Newt Gingrich said on ABC's "This Week" that the tweet Friday "didn't help him." But he added "he's been a fighter his whole life. He is infuriated, and legitimately, in my judgment, by this whole Russian baloney. And notice how it's evolving."

Sekulow, the chief counsel at the American Center for Law and Justice since 1990, defended Trump's use of social media, saying: "He's able to communicate with 107 million people on his various social media platforms on a regular basis as he needs to, so he can directly reach a lot of people."