Donald Trump: has "no problem" talking to Kim Jong Un

Presumptive GOP nominee, Donald Trump told Reuters on Tuesday that he would "have no problem" speaking to the repressive leader of North Korea, Kim Jong Un, in an effort to stop the country's rogue nuclear program.

"I would speak to him -- I would have no problem speaking to him," Trump said to Reuters.

The interview focused mostly on Trump's foreign policy approach, which has shifted several times since launching his campaign last year. It was published hours before the businessman won the Oregon primary and his campaign announced the formation of two joint fundraising ventures with the Republican National Committee.

Trump was outwardly critical of Russian President Vladimir Putin's approach to handling Ukraine , a rare criticism, given his warm words towards the Russian leader over the course of the campaign cycle.

"The fact that [Putin] said good things about me doesn't mean that it's going to help him in a negotiation. It won't help him at all," Trump told Reuters.

Last winter, Putin called Trump "bright and talented." Trump has said repeatedly on the campaign trail he would "get along very well" with Putin.

Trump seemed to reverse previous criticism for another world leader, British Prime Minister David Cameron.

Earlier this week, Trump said, "It looks like we're not going to have a very good relationship," referring to Cameron, in an interview with ITV's Piers Morgan. Cameron has been critical for months of Trump's plan to temporarily bar all Muslims from entering the United States, once calling it "divisive, stupid and wrong."

Trump seemed to have forgotten his earlier assessment, telling Reuters, "I'm sure I'll have a good relationship with him," even though Cameron has "plenty of problems."

Trump, who has shown himself to be a climate change skeptic, said that he would "at a minimum" renegotiate the Paris climate accord, a non-binding treaty that was signed by more than 170 countries in April, and that aims to lower greenhouse emissions all over the world. He claimed it unfairly favors China.

"I will be looking at that very, very seriously," Trump said. "And at a minimum I will be renegotiating those agreements, at a minimum. And at a maximum I may do something else."