Trump on potential war between Japan and North Korea: 'If they do, they do'

(CNN)   Donald Trump on Saturday reiterated his belief that Japan should arm itself to deter a threat from North Korea rather than have the U.S. military protect the longtime ally against the rogue nuclear nation. Meanwhile, Trump throughout the day maintained that the U.S. should pressure NATO member states to begin "paying their fair share."

"I would rather have them not arm, but I'm not going to continue to lose this tremendous amount of money. And frankly, the case could be made that let them protect themselves against North Korea. They'd probably wipe them out pretty quick," Trump said at a campaign event in Wasau, Wisconsin, Saturday afternoon.

The GOP front-runner added, "If they fight, you know what, that'd be a terrible thing. Terrible. ... But if they do, they do."

Earlier this week, Trump raised eyebrows and startled Japan and South Korea, two of America's strongest allies, with the suggestion that the U.S. military should be withdrawn from their shores, with nuclear weapons replacing them.

There are currently 54,000 U.S. troops stationed in Japan and 28,500 in South Korea.

"Japan is better if it protects itself against this maniac of North Korea," Trump told CNN's Anderson Cooper on Tuesday. "We are better off frankly if South Korea is going to start protecting itself ... they have to protect themselves or they have to pay us."

Concerned about the statement, Japan's Prime Minister Shinzo Abe responded publicly to the statement, saying, "whoever will become the next president of the United States, the Japan-U.S. alliance is the cornerstone of Japan's diplomacy."

And President Barack Obama himself weighed in on the comments at a news conference on Friday, saying, "The person who made the statements doesn't know much about foreign policy or nuclear policy or the Korean Peninsula or the world generally."

But on Saturday, Trump again pointed to the spiraling U.S. debt as a key reason for the country to rethink its military commitments abroad.

"We can't be the policeman to the world and have $19 trillion in debt, going up to $21 trillion," Trump said.

'Not paying their fair share'

Trump, who appeared at three campaign events throughout Wisconsin on Saturday, also reiterated his claim that many of the nations in NATO are "not paying their fair share."

"That means we are protecting them and they are getting all sorts of military protection and other things, and they're ripping off the United States, and they're ripping you off," Trump said at a rally in Racine, Wisconsin. "I don't care, I don't want to do that. Either they pay up, including the past deficiencies, or they have to get out."

At Racine, Trump also said he "will make a long statement about NATO," but it was unclear if he was referring to an upcoming speech or policy paper. A message left with Trump campaign spokeswoman Hope Hicks was not immediately returned on Saturday.

Last month, Trump said the U.S. should rethink its involvement with the alliance because it costs too much money. He told CNN's Wolf Blitzer that the U.S. pays a disproportionate amount to NATO to ensure the security of allies.

He doubled down on this position at the CNN town hall event on Tuesday, telling Cooper NATO is "obsolete" following the demise of the Soviet Union and the threat posed by terrorism.

But speaking Saturday night at an event in Eau Claire, Trump conceded that his knowledge about the alliance was limited.

"I know about NATO. I'm not an expert on NATO," Trump said, "but I have a lot of common sense."