Just hours prior to the expected blockbuster testimony from former acting U.S. Attorney General Sally Yates, the news that President Donald Trump was warned by President Barack Obama not to hire General Michael Flynn as his National Security Adviser, according to an exclusive NBC News report. The source of the news, reports NBC News, are three former Obama administration officials.

Less than forty-eight hours after defeating Hillary Clinton in the general election, Trump met with Obama in the Oval Office of the White House for a 90-minute conversation.

Trump said at the time that the meeting could have gone much longer, it went so well. And apparently, the conversation about general flynn came up then.

Trump White House responds to the NBC News story Flynn story

NBC News has asked the White House press office for a response to the news, and a senior official questioned why the Obama administration renewed his security clearance. They also said Trump took the remarks from Obama as in "jest" according to a tweet from NBC's Peter Alexander. It was President Obama who fired General Flynn as head of the Defense Intelligence Agency because of his uneven temperament and gross mismanagement.

Fast, forward three weeks into the Trump administration, General Flynn was fired by Trump himself for the stated reason that Flynn lied to Vice President Mike Pence.

This is where acting AG Sally Yates entered the picture. The 27-year career prosecutor at the Department of Justice warned aWhte House counsel about Flynn's being misleading about conversations he had with the Russian ambassador to the United States, Sergey Kislyak.

President Trump tweets about the AG Sally Yates testimony

A nervous President Trump has been tweeting about the upcoming testimony this afternoon.

He tweeted about what he called "classified information" and leaking it to the press. AG Yates had approached White House counsel Donald McGahn.

In the White House, WH Press Secretary Sean Spicer and Trump's Chief of Staff Reince Priebus dismissed the meeting between Yates and the White House counsel as more of a "heads up" rather than a warning.

James Clapper, the former director of National Intelligence, who succeeded the fired General Flynn in 2014, will also testify with Ms. Yates. they will appear before a Senate Judiciary subcommittee. With the testimony still on his mind, Trump tweeted earlier about Flynn and Obama.

In spite of Trump's complaint that Obama had already renewed Flynn's security clearance, a national security adviser clearance would have required a much higher level of vetting. Flynn is in trouble for representing the country of Turkey as a lobbyist while working on the campaign for Trump. He is also under heavy scrutiny for his paid visit to Russia seated with Russian strongman, Vladimir Putin.