There is "no doubt" the United States is committed to its fellow NATO member countries, Secretary of Defense James Mattis said in an interview with "Face the Nation" on Saturday.

During the campaign, then-candidate Donald Trump called NATO "obsolete," saying in a Washington Post interview that while NATO was a good concept, "it is not as good as it was when it first evolved." After taking office, President Trump changed his position following a meeting with NATO Secretary General Jens Stoltenberg. He said during a press conference last month that NATO is "no longer obsolete."

Mattis told "Face the Nation" host John Dickerson that the question is not whether the United States is with NATO, but instead how the U.S. and NATO can work together.

Issues they can work on include the "various forms" of attack that NATO allies face, Mattis said. They range from an active insurgency in Turkey to attacks like the one last week in Manchester.

"We have seen the terrorist threat, especially against the southern nations of NATO," Mattis said.

Mattis also highlighted Russia as a threat in the developing arena of cyberattacks against countries.

"Through its activities, shattered trust with a number of nations, especially along the eastern periphery," Mattis said. "The Russians have mucked around inside other people's elections. So, yes, NATO recognizes the shifting sense of the threat."

To help combat the threat, Mr. Trump has called on the fellow members of NATO to increase their spending on defense -- something Mattis said is working, as this is the second year in a row that there was an increase in military spending.

"Taken together, the non-U.S. members of NATO spend four times as much on military defense than Russia does," Mattis said. "So this is no insignificant amount."