Cruz backs former UN Ambassador John Bolton to replace Flynn

Sen. Ted CruzRafael (Ted) Edward CruzSenators push to clear backlog in testing rape kits Russia raises problems for GOP candidates Deal to fix family separations hits snag in the Senate MORE (R-Texas) on Friday threw his support behind former United Nations Ambassador John Bolton to replace Michael Flynn as President Trump's national security adviser.

"He's someone who understands the world. He understands the threats of radical Islamic terrorism," Cruz told CNN's Manu Raju. "He understands the threats of an over-aggressive [Russian President Vladimir] Putin."

"And at the same, I think he has demonstrated an understanding that we should be reluctant to use military force. That we should do so only when absolutely necessary."

Bolton, a foreign policy hawk who served as President George W. Bush's ambassador to the U.N., has also been a rumored pick for deputy secretary of State. 

Despite Cruz's approval, some Senate Republicans, such as Sen. Rand PaulRandal (Rand) Howard PaulGOP leader blocks resolution backing intelligence community on Russia Rand Paul blocks Sanders's Russia resolution, calls it 'crazy hatred' against Trump McCain: Trump plays into 'Putin's hands' by attacking Montenegro, questioning NATO obligations MORE (R-Ky.), have fiercely opposed Bolton's appointment to the Trump administration.

Further complicating an appointment, Bolton was a staunch supporter of the U.S. invasion of Iraq in 2003. Trump has criticized the war after initially supporting the invasion, calling into question whether their perspectives will align.

Flynn abruptly resigned on Monday amid revelations that he may have mislead Vice President Pence about a phone call Flynn had with the Russian ambassador.

The president offered the job to retired Vice Adm. Robert Harward after Flynn's resignation, but Harward turned down the offer.