With Japan, the United States and South Korea condemning the provision of military equipment and munitions by North Korea to Russia for use in the war in Ukraine, the three countries are closely monitoring what Moscow will give or may have given Pyongyang in return.
There are concerns about a potential transfer by Russia to North Korea of nuclear- and ballistic missile-related technology in Pyongyang's pursuit, for example, of a military spy satellite and a nuclear-powered submarine.
If such a deal occurred, it could further undermine regional security and the international nonproliferation regime -- a development that would also affect China, the main economic and diplomatic benefactor of North Korea.
Some Russian affairs experts believe the provision of such advanced, sensitive technology is unlikely, and that Russian aid is limited to energy and food, and possibly dated weapons.
"North Korea wants satellite technology, improved missile technology and submarine technology," said James Brown, a professor of political science at Temple University Japan Campus in Tokyo. "Russia might like to give the impression of a willingness to provide those technologies, but in reality, they would be reluctant to."
Pyongyang is believed to be preparing to launch a military reconnaissance satellite, possibly with assistance and advice from Moscow following a meeting between North Korean leader Kim Jong Un and Russian President Vladimir Putin in September in the Russian Far East. Details of the meeting are unknown.
After two failed attempts in May and August, North Korea had said it would make a third attempt in October, but no such launch has happened. Speculation about military cooperation grew after Russian Defense Minister Sergei Shoigu visited North Korea in July.
"Although they missed the October date, it could happen in November or later," Brown said in an interview. "But Kim Jong Un's visit was only in September, so even if the Russians gave them some technology, you can't use it yet. It takes a long time."
Meeting on the sidelines of the Asia-Pacific Economic Cooperation forum summit in San Francisco last week, Japanese Foreign Minister Yoko Kamikawa, U.S. Secretary of State Antony Blinken and South Korean Foreign Minister Park Jin affirmed Russia-North Korea military cooperation poses a "serious threat" to international peace and stability, according to the South Korean Foreign Ministry.
In a Nov. 7-8 meeting in Tokyo, Kamikawa, Blinken and their counterparts from the Group of Seven industrialized nations strongly condemned arms transfers from North Korea to Russia -- which are in violation of U.N. Security Council resolutions -- and urged the two countries to "immediately cease all such activities."
These meetings came after South Korean officials said on Nov. 2 that the South's military estimates North Korea had shipped about 2,000 containers of military equipment and munitions to Russia, up from 1,000 containers revealed by the White House on Oct. 13.
South Korea's National Intelligence Service believes North Korea delivered more than 1 million artillery shells to Russia -- roughly amounting to two months' worth of supplies to the country -- in over 10 shipments since early August.
Citing U.S. intelligence and other sources of information, Akiko Yoshioka, a research fellow at the Canon Institute for Global Studies in Tokyo, said North Korea delivered munitions to Russia -- including the mercenary group Wagner -- and Moscow supplied oil and grains to Pyongyang well before the Sept. 13 meeting between Putin and Kim at the Vostochny Cosmodrome space center.
"Mr. Putin may have expressed readiness to help Mr. Kim launch satellites. But I'm skeptical about Russia offering advanced, expensive missile technologies in return for a limited amount of North Korean ammunition," Yoshioka said in a separate interview.
"Military cooperation could involve conventional capabilities, but not nuclear and missile capabilities because Russia is against a nuclear-armed North Korea."
She also cited Russia's concern about the possibility that Pyongyang may resell missile technologies to third parties, as well as China's call for a stable North Korea, not a more provocative one.
Besides energy and food aid, Moscow may allow an estimated several thousand North Korean workers left in Russia to stay in the country -- which would also violate a U.N. Security Council resolution -- and engage in construction work as Russia suffers a labor shortage from its campaign against Ukraine, according to Yoshioka.
Yoshioka and Brown shared the view that the Putin-Kim meeting was a diplomatic show, arguing Putin used the event to threaten Tokyo, Washington and Seoul that if they step up sanctions on Russia and extend more military aid to Ukraine, Moscow will deliberately entertain the idea of providing Pyongyang with missile technology.
The choice of the meeting venue was significant in terms of sending such a message to relevant countries, the experts said.
Putin is also playing a game with Kim, according to Brown.
"I think the Russians are providing the North Koreans with empty promises," he said. "By taking Kim Jong Un around the spaceport, the rocket base, around the military facilities elsewhere, Putin is encouraging the idea that 'Maybe a little bit later when our relationship is closer, then we will perhaps provide technology.'"