President Donald Trump on Monday defended his decision to hire former National Security Adviser Michael Flynn, blaming former President Barack Obama for failing to catch red flags in Flynn's background. He also suggested that members of the Senate Judiciary Committee question former acting Attorney General Sally Flynn about leaks when she testifies Monday afternoon.

Trump on Monday morning tweeted that Obama's administration – not his own – bore the responsibility for vetting Flynn, who has come under scrutiny for accepting money from foreign sources in 2015 and 2016.

"General Flynn was given the highest security clearance by the Obama Administration - but the Fake News seldom likes talking about that," he wrote.

However, Obama warned Trump against hiring Flynn, according to three former Obama administration officials who told NBC News on Monday that the warning came just days after the election when the two men met for 90 minutes in the Oval Office.

In other tweets, Trump demanded members of the Senate panel question Yates about leaks from within the Justice Department that have revealed elements of the FBI's investigation into whether Trump's campaign colluded with Russia to hack the election.

"Ask Sally Yates, under oath, if she knows how classified information got into the newspapers soon after she explained it to W.H. Counsel," he added.

Yates, a deputy attorney general under former President Barack Obama beginning in 2015, was fired by Trump on Jan. 30 for refusing to defend his executive order barring travel from some Muslim-majority countries.

She is expected to testify before the Senate panel on Monday that she warned the White House about Flynn's contacts with Russian ambassador Sergey Kislyak on Jan. 26, four days before she was fired.

Flynn is one of several members of Trump's campaign team under investigation for his connections to Russian officials, and could face criminal prosecution for accepting tens of thousands of dollars from Russian organizations, including the state-owned news channel RT, connected to a 2015 trip in which he spoke and appeared at an event with Russian President Vladimir Putin.

The White House has sought to shift the blame for hiring Flynn despite his activities in Russia, some of which were reported on during the campaign, claiming that they trusted investigators who renewed Flynn's security clearance in 2016 to have surfaced any problems, even though Flynn himself was obligated to disclose them but did not. Flynn was fired as head of Obama's Defense Intelligence Agency in 2014.

Yates was initially scheduled to testify in March before the House Intelligence Committee, which is also probing the connections between Trump and Russia. That appearance was canceled amid accusations from Democrats that the White House was pressuring its allies in Congress to prevent her from speaking out.

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