Those comments came after he said Tokyo should do more to protect its own concerns rather than relying on the US after a Japanese tanker was damaged in an attack in the Straits of Hormuz that Washington has blamed on Iran.
Officials in Tokyo and Washington were quick to declare that the security relationship remains solid, although those claims were undermined by Mr Trump’s subsequent comments on Fox.
The president has levelled similar accusations against a number of Washington’s closest security partners, including South Korea, apparently in an effort to force the government to pay more for the US troops that are stationed in the country.
Emanuel Pastreich, president of the Asia Institute in Seoul, said other long-standing allies in the region, including Taiwan and Australia, will be looking on with concern.
“At a time of unprecedented tension in this region, this is the last thing that America’s allies want to hear”, he told The Telegraph. “And while Mr Trump is upsetting his friends, China and North Korea will be looking on and sensing that this is an opportunity”.
Japan has refrained from replying to the president’s comments immediately before he arrived in Osaka for the G20 talks, although a government official did comment to The Telegraph that, “all this does is trigger discussions in Beijing and Pyongyang about the decreasing US influence in north-east Asia”.