As discussions continue over when and where a summit between U.S. President Donald Trump and North Korean leader Kim Jong Un will take place, Japan’s former chief negotiator for multilateral talks aimed at ending the North’s nuclear program on Tuesday warned that the current U.S. administration has virtually no expertise on Pyongyang.

“Almost nobody in the Trump administration has much knowledge about North Korea,” Mitoji Yabunaka, a professor at Kyoto’s Ritsumeikan University, said at a speech in Kyoto.

Referring to John Bolton, the hawkish former U.N. ambassador who took over Monday as Trump’s national security adviser, Yabunaka said he “comes across as more of a television commentator, and there is a shortage of North Korean experts in the State Department.”

Yabunaka, a former vice minister at the Foreign Ministry, said that while Trump and Kim have agreed to hold a summit, there is a problem on the U.S. side.

Yabunaka negotiated with North Korea in 2003 and 2004 as Japan’s representative to the six-party talks, which also involved China, Russia, South Korea and the United States. The nuclear talks have been stalled since late 2008.

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In response to U.S. confirmation of media reports that there is an agreement to discuss the denuclearization of the Korean Peninsula, he said that this is an issue, and a process, that Trump may not fully comprehend.

When Prime Minister Shinzo Abe travels to the United States from April 17 to April 20, he may be one of the few people Trump will listen to on North Korea.

But Yabunaka cautioned that the chummy relationship between the two men was not enough this time.

“The meeting can’t just be one of playing golf. Trump has to hear things about North Korea from Abe and think about things he may not want to think about,” he said.

Even as it is important to stay close with the U.S. on North Korea, Japan also needs to work more smoothly with China. While relations between the two Asian countries are said to be improving somewhat, Yabunaka said that for Tokyo, there are four basic problems.

“Japan can’t accept the fact that China has become a huge power, and believes that the history problem is because of anti-Japanese sentiment. There is also the problem of Japan not knowing what China will do, and of territorial issues like the Senkakus,” he said.