Rattled Japan blasts Trump's call to arm itself with nuclear weapons to replace US military presence.

He's nowhere near the White House yet, but the possibility he could be president has so disturbed Japan and South Korea now that they know his foreign policy that they've lashed out against the candidate. Trump stunned two of America's strongest allies by indicating that as president he would withdraw US military presence from their countries, and warned that they would have to rely on nuclear weapons for defense instead. There are currently 54,000 American 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 at the network's town hall meeting for the candidates. "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."

It seemed particularly preposterous to suggest that Japan should house nuclear weapons. "It is impossible that Japan will arm itself with nuclear weapons," said Foreign Minister Fumio Kishida. Japan, which suffered terribly in the US nuclear attacks at Hiroshima and Nagasaki is stridently pacifist.

Japan's Prime Minister Shinzo Abe immediately warned that "whoever will become the next president of the United States" must realise that the "Japan-US alliance is the cornerstone of Japan's diplomacy," reported CNN.

The US has long opposed nuclear weapons in South Korea, a position supported by the international community. "It's hard for me to imagine why it would be a good idea to give the North Koreans any justification or any incentive to further accelerate their nuclear weapons programme. It doesn't make any sense," said White House Press Secretary Josh Ernest.

Former US ambassador to South Korea Christopher Hill told CNN:: "I don't know what he's [Trump] talking about but clearly neither does he."