Trump willing to 'sit down' with North Korea's Kim Jong Un

President Trump said Wednesday he is willing to negotiate directly with Kim Jong Un over North Korea’s nuclear weapons program but expressed doubts it would ultimately work.

“I’d sit down, but I’m not sure that sitting down will solve the problem,” Trump said in an Oval Office interview with Reuters.

Trump would not say whether he has spoken with Kim, whom he has dismissively nicknamed “little rocket man.”

He pointed out that negotiations undertaken by previous administrations with the North Korean regime had not been successful.

“I‘m not sure that talks will lead to anything meaningful,” Trump said. “They’ve talked for 25 years and they’ve taken advantage of our presidents, of our previous presidents.”

MCMASTER ATTENDED SECRET MEETING ON NORTH KOREA

In the interview, Trump praised China for restricting oil and coal from going to North Korea but called out Russia.

“Russia is not helping us at all with North Korea,” Trump said. “What China is helping us with, Russia is denting. In other words, Russia is making up for some of what China is doing.”

Trump’s national security adviser, H.R. McMaster, secretly traveled to San Francisco over the weekend for a meeting on North Korea’s nuclear weapons program, Fox News has confirmed.

According to sources, McMaster met with officials from South Korea and Japan, including Shotaro Yachi, the director of the Japanese national security council.

During the meeting, the group discussed the newly-resumed communications between North Korea and South Korea. They also agreed that these renewed communications – and agreement for North Korea to send athletes to the Winter Olympics in Pyeongchang, South Korea next month -- are diversions and have no effect on North Korea leader Kim Jong Un’s nuclear weapons program, the sources said. 

Fox News’ John Roberts contributed to this report.

Alex Pappas is a politics reporter at FoxNews.com. Follow him on Twitter at @AlexPappas.