Former Secretary of Defense Robert Gates called the White House's decision to keep the press out of a recent meeting with Russian officials "pretty odd" because past presidents openly met with foreign leaders of countries who were not necessarily allies.

"For a long time, Soviet foreign ministers would come in to see the president all the time, routinely. Jimmy Carter stopped that after the invasion of Afghanistan. Ronald Reagan resumed it in 1984, I think. And so the fact of a meeting like that I think is not that big a deal," Gates told "Face the Nation" host John Dickerson in an interview on CBS that aired Sunday.

Gates, who served as top U.S. diplomat under former Presidents George W. Bush and Barack Obama, said Trump smiling in pictures with Russian Ambassador Sergei Kislyak and Russian Foreign Minister Sergey Lavrov was precedented, while the policy approach has actually been harsher than in the past.

"Well, I think in the policies that have been followed since the president came into office, there really hasn't been any slack cut for the Russians. And I think one of the things that has surprised people has been that the relationship between the United States and Russia has in fact deteriorated since the election," Gates said.

"The administration, the contrast between the way they have treated the Russians and the way they have reacted to the Chinese is pretty stark. So, you know, having smiles in the Oval Office, I don't know, maybe I'm just getting too old, but I don't think that's that big a deal. It's in their policies and in their actions that really matters. And in those — in those arenas, I think they've been pretty tough-minded," he finished.

Gates said Trump's unique approach to North Korea is a welcome change of pace compared to the previous three administrations.

"We've had three administrations follow a pretty consistent policy toward North Korea, and it really hasn't gotten us anywhere. So the notion of disrupting and sort of putting the Chinese on notice that it's no longer business as usual for the United States I think is a good thing," Gates said, adding it's possible China may not have as much sway on North Korea as Trump hopes.

Gates also defended Trump's domestic leadership style, praising his "disruptive approach" to reforming the "fat and sloppy" government.