North Korean leader Kim Jong Un is trying to create friction between Tokyo and Seoul, South Korea, and undermine their trilateral relations with the United States as security cooperation among them deepens, analysts said.
Washington, Seoul and Tokyo conducted trilateral naval drills in the international waters south of Jeju Island from Monday to Wednesday, said South Korea's Joint Chiefs of Staff (JCS).
The exercises involving nine ships, including the USS Carl Vinson, a nuclear-powered aircraft carrier, were aimed at enhancing deterrence against North Korean nuclear, missile and underwater threats, the JCS said.
North Korea is taking an increasingly hostile stance toward South Korea. Calling for the amendment of its constitution to refer to South Korea as its "principal enemy," Kim said Pyongyang should plan for occupying South Korea if war breaks out.
He made the remarks in a speech on Monday to the Supreme Assembly, the country's rubber-stamp parliament, said state media KCNA.
A day earlier, North Korea test-fired what it said was a solid fuel intermediate range ballistic missile with a hypersonic warhead.
Pyongyang also fired more than 200 rounds of artillery shells near Yeonpyeong Island on a disputed maritime border with South Korea on January 5 and more than 60 rounds near the same island on January 7. Yeonpyeong Island is about 120 kilometers west of Seoul.
While escalating tensions on the Korean Peninsula, Kim sent a message to Prime Minister Fumio Kishida on January 5 conveying sympathy over a powerful earthquake that shook Ishikawa prefecture, leaving at least 200 people dead and more than 200 missing as the new year began.
In the message, Kim expressed "his deep sympathy and condolences" to Kishida for losses caused by the earthquake, KCNA reported on January 6.
Analysts said although North Korea has relayed condolence messages to Japan after disasters in the past, this is the first time Kim personally reached out to a Japanese prime minister.
"While Kim Jong Un may wish to drive a wedge between Japan and the ROK, the real intention, subtle but still real, is to drive a wedge between Japan and America, in spite of last year's successes at Camp David in the trilateral summit," said Kenneth Dekleva, a senior fellow at the George H.W. Bush Foundation for U.S.-China Relations.
At the Camp David summit, U.S. President Joe Biden, South Korean President Yoon Suk Yeol, and Kishida agreed to cooperate on multiple measures to bolster deterrence against North Korea.
Dekleva, who served as a State Department psychiatrist analyzing foreign leaders including Kim from 2006 to 2016, continued, "Another intention of equal importance is to test the U.S.-ROK relationship, especially given the recent dangerous, bellicose threats of war made recently by Kim Jong Un."
Kim ordered his military forces to prepare for war with the U.S. and "South Korean puppets and Japs," according to KCNA, describing Kim's speech made at a planning meeting of his ruling Workers' Party on December 31.
Pyongyang has been critical of the trilateral ties forged after Seoul and Tokyo mended relations in March. Disputes rooted in Japan's colonization of the Korean Peninsula from 1910 to 1945 had strained relations for decades.
Ken Gause, an expert on North Korea's leadership and political system at the Center for Naval Analyses, said Kim's message also signals Pyongyang could be "keeping its options open for engagement."
"North Korea is trying to put Japan in a situation where it has to choose between its own self-interest and the self-interest of the alliance as a whole," he said.
Kishida said in May that he is willing to meet Kim to discuss the return of Japanese who were abducted by North Korea in the 1960s and 1970s.
At North Korea's summit with Japanese Prime Minister Junichiro Koizumi in September 2002, Kim's father, Kim Jong Il, admitted the country had abducted 12 Japanese nationals. North Korea returned five of them to Japan in October of that year.
Japan says North Korea abducted 17 Japanese citizens in the 1970s to 1980s.
Shihoko Goto, Asia program director at the Wilson Center, said, "The abduction issue remains a highly emotional agenda in Japan, and moving forward to seek a resolution is high on the agenda of Kishida's government."
She added that Kim's message of condolence "was seen favorably in Tokyo and seen as an opportunity for greater dialogue, if not improved relations, between the two countries."
However, she said, Tokyo will be "in lockstep" with Seoul and Washington in deterring North Korea, as Pyongyang also is "an existential threat" to Japan.