Donald Trump, who has passed the number of delegates needed to secure the Republican presidential nomination, on Thursday fired back at President Barack Obama, after the latter said that Trump has “rattled” world leaders.

“When you rattle someone, that’s good,” Trump told reporters in North Dakota, according to The Washington Times. “As you know, many of the countries in our world … have been absolutely abusing us and [taking] advantage of us.

“We’re going to have great relationships with these countries, but if they’re rattled in a friendly way, that’s a good thing … not a bad thing,” added Trump.

Obama, who is in Japan, told reporters earlier Thursday that many of Trump’s proposals “display either ignorance of world affairs or a cavalier attitude or an interest in getting tweets and headlines instead of actually thinking through what it is that is required to keep America safe and secure and prosperous and what’s required to keep the world on an even keel.”

Trump in response said Obama is a president who’s done a “horrible job.”

“He’s a president who’s allowed many of these countries to totally take advantage of him, and us, unfortunately, and he’s got to say something,” he charged, according to The Washington Times.

Trump said that it is “unusual that every time [Obama] has a press conference, he’s talking about me.”

“But I will say this: he is a man who shouldn’t be really airing his difficulties, and he shouldn’t be airing what he’s airing where he is right now, and I think that you’re going to see it stop pretty soon,” he added.

“President Obama, you see what’s happened…we’re a divided country…we’re going to solve those problems,” vowed Trump.