Taking a page from former U.S. leader Richard Nixon, current President Donald Trump has warned China that it must do more to rein in North Korea’s nuclear ambitions or face “a big problem” with “warrior nation” Japan.

“Japan is a warrior nation, and I tell China and I tell everyone else that listens, I mean, you’re gonna have yourself a big problem with Japan pretty soon if you allow this to continue with North Korea,” Trump said during an interview on the Fox News program “The Ingraham Angle” on Thursday, a day before departing on his first Asia tour as president.

It was unclear what the U.S. leader was referring to, in terms of a “big problem,” but Trump had suggested during his successful campaign for president that he would be open to Japan acquiring its own nuclear weapons.

China has looked warily at recent moves to loosen postwar constraints imposed on Japan’s military and has long been suspicious of Tokyo’s large plutonium stockpile.

In February 1972, as part of his successful efforts to normalize ties with Beijing, Nixon took a similar tack with then-Chinese Premier Zhou Enlai, who was anxious of Japanese remilitarization, claiming that restraining Tokyo was also in the U.S. interest, according to minutes of their meeting fully declassified in 2003.

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Trump was scheduled to kick off his Asia tour in Japan from Sunday, when he was to meet with Prime Minister Shinzo Abe, who has joined the U.S. president in his “maximum pressure” approach to nuclear-armed North Korea.

He will also visit China from Wednesday to Thursday and meet President Xi Jinping.

Trump said in Thursday’s interview that Xi had been “pretty terrific” on North Korea and that “China is helping us,” but is widely expected to urge Beijing to do more on the issue.

Regional tensions have soared over Pyongyang’s ballistic missile and atomic programs, which in recent months have seen it test long-range missiles and carry out its sixth nuclear blast. It has also lobbed two intermediate-range missiles designed to carry nuclear payloads over Hokkaido, stoking concern in Tokyo.

Still, experts say that any push by Japan to build nuclear weapons currently remains unlikely given the low levels of public support and because of the ensuing arms race in Asia it would almost assuredly unleash.

“The potential for Japan and South Korea to develop nuclear weapons … is extremely remote … in the near-medium term,” said J. Berkshire Miller, a senior visiting fellow with the Japan Institute of International Affairs in Tokyo.

Trump’s warning “seems more of a leverage threat rather than anything tangible,” he added.

More immediately, Japan under Abe has moved to slowly unshackle itself from constraints imposed after its loss in World War II, including by passing security legislation that has set the stage for U.S. and Japanese troops to work more closely together than ever.

And with tensions on the Korean Peninsula hitting recent highs, Abe has overseen a more muscular response out of Tokyo to that crisis, often dispatching the Self-Defense Forces for joint exercises with the U.S. as part of his push to make them a better and more capable military.

Miller said Trump’s “unsophisticated allusion to the idea of potential remilitarization in Japan” runs counter to the usual terminology around the strength of the U.S.-Japan alliance.

“I am not sure there is much strategic thinking behind the remarks, rather it is another display of Trump’s usual shock and awe style of leveraging positions” on China, Miller said.

The danger, however, is that Trump could inadvertently give ammunition to Beijing, which has fostered a narrative that Japan seeks to rearm and contain China.

“Trump can help fuel erroneous narratives that come largely out of China regarding Japan’s so-called remilitarization,” Miller said. “Rather than outline the U.S.-Japan partnership and the positive role Japan has played since World War II — a default line for U.S. administrations for decades — Trump is opening the door to legitimatize Beijing’s highly politicized line on Japan’s security and defense evolution.”