"Jeb is so wrong. Jeb is absolutely [wrong]," Trump said at the GOP debates in Greenville, South Carolina, broadcast by CBS.
Addressing vocal opposition from the audience, Trump claimed "that’s Jeb’s special interests and lobbyists talking." He was met with applause by decrying $5 trillion spent on Mideast wars "because of thinking like that."
Bush retorted by claiming that Russia "is not going to be an ally of the United States…They’re attacking troops that we’re supporting."
Trump had previously expressed support for Russian President Vladimir Putin and welcomed Moscow’s role in anti-Islamic State efforts in Syria.