World leaders are "rattled" by the presumptive nomination of Donald Trump as the Republican presidential candidate in this year's US elections, President Barack Obama said Thursday on the sidelines of a G7 summit in Japan.
Countries around the world are paying "very close attention" to the November elections, Obama told journalists in the Japanese resort of Ise-Shima, noting that the United States is "at the heart of the international order."
"They are rattled by [Trump], and for good reason, because a lot of the proposals that he has made display either ignorance of world affairs, or a cavalier attitude or an interest in getting tweets and headlines," rather than seeking to keep the US safe and the world "on an even keel," he added.
Trump, speaking to reporters in the US state of North Dakota, dismissed Obama's criticism and suggested it was to the United States' advantage to "rattle" other nations.
"Many of the countries in our world, a beautiful world, have been absolutely abusing us," Trump said. "If they're rattled in a friendly way that's a good thing not a bad thing."
Trump also said Obama should not be criticizing domestic political opponents while abroad, a practice that US politicians typically refrained from. "He shouldn't be airing what he's airing where he is right now," Trump said.
The wealthy businessman has criticized Washington's large defence presence in areas such as Japan, South Korea and the Middle East, and has also suggested that the US could reduce its role in NATO.
Last month, the presidential hopeful told broadcaster CNN that it might be advantageous for Japan and South Korea to have their own nuclear arsenals, and that he wouldn't rule out using nuclear weapons in Europe.