Japanese PM Shinzo Abe lost no time in responding to reports that Kim Jong Un had traveled to Beijing to meet the Chinese President Xi Jinping earlier this week.

Abe reiterated that North Korea must give up its nuclear weapons and missile programs and announced on Wednesday that he will travel to Washington in mid-April to meet US President Donald Trump and "coordinate policy" on Pyongyang.

The Japanese leader is likely to encourage Trump to continue to take a hard line on Pyongyang and to insist that international sanctions are working and to not make concessions if the planned summit with Kim goes ahead

South Korean officials announced on Thursday that North and South Korea would hold their first summit in more than a decade on April 27. 

Abe is expected to urge the US president to include a human rights component to their talks, specifically a commitment from North Korea to return all Japanese nationals that have been abducted to train the regime's secret agents.

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There is concern in Japan that although Trump may be an effective and ruthless businessman, he is up against a North Korean leader who, while young, is clearly adept at playing competing nations off each other – a skill that three generations of the Kim family have built up over more than 70 years.

North Korea's charm offensive

South Korea appears to have been convinced that the North is genuine in its desire to rebuild cross-border ties. Now China is on the receiving end of Pyongyang's charm offensive. Tokyo senses that Washington might be willing to make friends with Kim's regime, leaving Japan out in the cold.

There is also fear that Trump could strike a deal that ignores many of Japan's interests simply because he wants a diplomatic victory over a regime that has been a thorn in America's side for decades and which previous administrations have failed to break. An agreement could also give him the air of a statesman.

"I think it is quite clear that Abe is desperate to meet Trump as soon as possible as things appear to have gone quite seriously wrong in the relationship very suddenly," said James Brown, an associate professor of international relations at the Tokyo campus of Temple University, told DW.

"Just a few weeks ago, Abe was being described as the 'Trump whisperer' because he had learned how to deal with the president," said Brown. "But then Japan was completely thrown when Trump agreed to meet Kim because it was a complete about-face from the previous policy of maximum pressure."

Brown added that by agreeing to talks, Trump has already effectively ceded the policy of maximum pressure. Although bringing in John Bolton as his point-man on Pyongyang may indicate that the president is attempting to revert to pressure as a tactic.

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Abe's position on Japanese abductees being held in North Korea is also likely to not have priority from the US president.

"This is a major issue for Japan, but also for Abe personally because the abductions is how he made his political name before becoming prime minister," Brown said.

"Other countries will sympathize and say it is sad for those who were abducted, but it is minor when compared with the threat posed by nuclear weapons and ballistic missile to millions in the US today."

Ultimately, Abe's biggest concern will be Japan potentially being left out of the process that is today bringing together North Korea, South Korea, the US and China.

Japan doesn't want its security concerns and the fate of its citizens becoming a footnote in the discussions.

Jun Okumura, a political analyst at the Meiji Institute for Global Affairs, told DW he believes the Japanese leader has good reason to be worried.

"Abe is going to go there [to Washington] and really try to pressure Trump to stand firm and make sure that Kim does not still have nuclear-tipped missiles when the talking is over," said Okumura, adding that the Japanese leader must emphasize that even Kim's medium-range missiles can reach Guam and Alaska, as well as the US troops stationed in South Korea and Japan.

"Abe is also going to play up the danger of proliferation if Kim is able to keep his weapons of mass destruction," said Okumura, adding that this would set a negative precedence for US interests in the Middle East.

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With China suddenly re-emerging as a supporter of North Korea, however, Trump may realize that he no longer has the ability to threaten Kim and he may instead opt to take "whatever promises he can get" from Pyongyang in the leaders' upcoming talks and claim victory. And that would leave Japan completely isolated, said Okumura.

"Japan has never had a great deal of direct leverage over North Korea and could only pressure the regime through the US, so there is a part of me that thinks it is stupid of Abe to go to Washington," Okumura said.

"He looks like a supplicant pleading with Trump, who will do whatever he wants to in the end anyway."

"Talks will put Japan in an even more disadvantageous position and are likely to leave Japan as the only nation standing firm against North Korea," he added.

But only time will tell if North Korea can be trusted as a member of the international community once again or if Japan's wariness is justified.