"Japan has been very isolated on the North Korean issue," said Richard McGregor, senior fellow at think tank the Lowy Institute in Australia.
Chinese President Xi Jinping and South Korean President Moon Jae-in have both met with Kim in the last few weeks. U.S. President Donald Trump, meanwhile, is expected to hold a meeting with Kim in coming weeks.
Because of those meetings, "for Japan, it was particularly important to try and play themselves back into this game, which of course, they are in the center of, whether they like it or not," McGregor told CNBC's "The Rundown."
The trilateral meeting, the first such event in three years, was held in Tokyo on Wednesday and came against the backdrop of domestic political concerns surrounding Abe.
On Wednesday, China, Japan and South Korea agreed to cooperate in seeking the denuclearization of the Korean Peninsula. Abe, for his part, praised efforts by the other two nations to engage North Korea and said further efforts on denuclearization were essential.