Donald Trump lived up to his controversial nature again Thursday, slamming former President George W. Bush for charging $100,000 to speak at a charity fundraiser for military veterans wounded in Iraq and Afghanistan, plus an additional $20,000 for a private jet to get there.

"You mean George Bush sends our soldiers into combat, they are severely wounded, and he wants $120,000 to make a boring speech to them?" Trump tweeted Thursday morning.

ABC News reported Wednesday that in 2012, Bush charged $100,000 to speak at a fundraiser for military veterans sponsored by the Texas-based Helping a Hero charity. A private jet was also provided to Bush so he could travel to the event, at a cost of $20,000. The previous year, former First Lady Laura Bush collected $50,000 to appear before the same charity.

"The point here is that a leader should not charge to speak on behalf of the men that he sent into combat, at any level, let alone the commander in chief," said Eddie Wright, a Marine who lost his hands in a 2004 rocket attack in Iraq, CNN reported.

Upon hearing the news, "The Donald" just couldn't resist throwing in a veiled jab at Bush's younger brother and Trump's Republican presidential rival Jeb Bush.

"Jeb's brother George insisted on a $100,000 fee and $20,000 for a private jet to speak at a charity for severely wounded vets. Not nice!" the billionaire real estate mogul tweeted.

Trump and Bush, a former Florida Governor, have been neck and neck in the polls, but in the latest YouGov poll released Thursday, Trump surged to the top of the GOP pack, garnering 15 percent support compared to the 11 percent received by Bush and Kentucky Sen. Rand Paul.

Trump's surge was at least partially thanks to the massive amount of media attention afforded to him following contentious remarks about how he believes many illegal Mexican immigrants are criminals.

Bush, whose wife is Mexican, took offense to Trump's remarks and a war of words broke out between the two.

On Wednesday, Trump said Bush's immigration reform policy has been influenced by his wife, reported The Hill. Trump had also previously retweeted and then deleted a comment that said, "Jeb Bush has to like the Mexican illegals because of his wife."

At a campaign stop in New Hampshire, Bush responded to the comments, saying, "You can love the Mexican culture, you can love your Mexican-American wife and also believe that we need to control the border," Bush said, according to The Washington Post. "This is a bizarre kind of idea that somehow you can have an affection for people in a different country and not think the rule of law should apply. This is ludicrous."

In an interview with Fox News on Wednesday, Bush said he's had enough of talking about Trump. "I'm done. I'm through. I gave my views. I just think that we need to be much more hopeful and optimistic about our ideology," reported Business Insider.