President Barack Obama declared Tuesday that foreign leaders are “rattled” by Donald Trump and have good reason to feel that way, as he accused the presumptive Republican presidential nominee of ignorance about world affairs.

Obama’s appraisal of the presidential campaign came on the sidelines of a Group of Seven markets that were advanced summit in Japan, the latest world assembling to be colored by global concerns about Trump. Obama said foreign leaders at the seminar are “surprised by the Republican nominee” and uncertain how seriously to take his pronouncements.

“They are rattled by it — and for good reason,” Obama said. “Because a lot of the suggestions he’s made display either ignorance of world affairs, or a cavalier attitude, or an interest in getting tweets and headlines.”

He compared that to suggestions that thoughtfully address what is needed to keep the U.S. safe and prosperous and “to keep the world on an even keel.”

Obama brushed off calls for Clinton and Sanders to move so that Democrats can unite behind one candidate to conclude the primary, arguing that this year’s Democratic nominees are not that ideologically divided. He likened the hard fought campaign between Sanders and Clinton to the one he waged with Clinton in 2008.

“During primaries, people get just a little grumpy with each other. Somebody’s supporter pops off and there’s a certain accumulation of aggravation,” Obama said. “Every little speed bump, clash trash talking that takes place is elevated.”

He encouraged both Democratic candidates to “strive to stick to the issues,” including the grumpiness frequently stems from voters’ frustration when the campaign rather becomes controlled by discussion about “personalities and character.”

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