SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - Top diplomats of China and Japan will visit Washington on Wednesday (May 23), media outlets reported Tuesday (May 22), ahead of a US-North Korea summit in June.

Chinese Foreign Minister Wang Yi will discuss issues concerning both the US and China with US ranking officials in Washington on Wednesday, a local media outlet reported, citing an unnamed source.

North Korea's denuclearisation, which is the main agenda item of the summit, will be discussed in Washington, according to the report.

Wang's visit comes as North Korea takes a harsher tone, threatening to scrap the meeting and taking issue with South Korea-US joint military exercises and denuclearisation plans Washington may be considering.

Experts say that Beijing likely wants to clarify its position regarding Trump's comments that China may be connected to recent developments surrounding North Korea through Wang's visit.

"China will explain it is not pushing North Korea to shift to a hard-line position, and Beijing is probably taken aback with Trump deflecting blame (for the current situation) toward them," said Go Myong Hyun, a research fellow at the Asan Institute for Policy Studies, adding that North Korea's denuclearisation and ongoing US-China trade issues would be the main topics discussed in Washington.

"Though it may seem China has massive clout over North Korea, it is actually North Korea that has the upper hand in the situation surrounding denuclearisation. The two surprise meetings between Xi Jinping and North Korean leader Kim Jong Un were actually arranged by Kim," he added.

Regarding the gap in Pyongyang and Washington's ideas on denuclearisation, Wang said it's crucial for both to "work towards the same direction, not the opposite," and that measures North Korea has taken to "ease tension on the Korean Peninsula should be acknowledged."

He said that "all parties, especially the United States, should cherish this opportunity for peace and should not work as a barrier."

The US has been expressing its preference for a swift and stringent denuclearisation process, as well as the complete dismantlement of the North's nuclear programme, while the North has been asking for a "phased and synchronous" method.

Japanese Foreign Minister Taro Kono's Washington trip will also fall in the same timeframe as Wang's, after changing his plan upon receiving the news that US Secretary of State Mike Pompeo would not attend the G-20 meeting in Argentina, reports said, citing Japan's Kyodo News.

Kono's initial plan was to meet Pompeo on the sidelines of the G-20 meeting, to discuss North Korea issues. He also recently expressed hope to share views on the US-North Korea summit.

Kono will deal with long-standing issue of Japanese nationals abducted by North Korean agents in the 1970s and 1980s, but the actual message will be to remind the US not to yield to the North's preferred steps toward denuclearisation, according to Go.

"The talks on expanding the US-North Korea summit agenda items to the issue of Japanese abductees will be raised at the table, but beneath it all, the core message will be not to be convinced by the North's request for 'phased and synchronous' measures," Go said.

Wang and Kono's visits comes on the heels of a meeting between Trump and South Korean President Moon Jae In in Washington early Wednesday.