A former U.S. Ambassador to NATO said President Trump "missed an opportunity" this morning by failing to substantially address the threat to Europe from Russia. 

Nicholas Burns, who served as NATO ambassador under President George W. Bush from 2001 to 2005,  said Trump must be the leader of NATO and speak for the organization at-large.

"He only fleetingly, in two or three words, condemned the threat from Russia. What's on the minds of those European leaders behind him? Vladimir Putin invading countries in Eastern Europe. They need American leadership to contain the Russians and the president barely mentioned that," he said on "America's Newsroom."

Burns recalled that after the 9/11 attacks, NATO partners came to the defense of the United States and fought in Afghanistan, but Trump failed to discuss that.

"He's not succeeding at becoming the leader that Ronald Reagan was or Bill Clinton or John F. Kennedy or Dwight D. Eisenhower. He needs to speak with more sophistication to an audience like those European leaders behind him," said Burns. 

He said Trump is "right" to bring up some NATO partner countries not living up to their commitments in terms of defense spending. 

Trump, speaking in Brussels at the dedication of a new NATO headquarters, said 23 of the 28 member nations are not paying what they should and that it’s "not fair" to the people of the United States. He said many of these nations owe "massive" amounts of money from previous years, AP reported.

Watch Burns' full reaction above and the full speech below.

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