The NATO secretary-general said the security concerns of the Western military alliance and Japan are ‘closely interconnected’.

Arriving in Tokyo from South Korea on Monday where he had urged Seoul to increase its military support for Ukraine, Stoltenberg said his trip was aimed at strengthening relations between NATO and “our highly valued partner” Japan.

“The war in Ukraine also demonstrates that our security is closely interconnected,” Stoltenberg said on Tuesday during a visit at the Iruma Air Base north of Tokyo.

“If President [Vladimir] Putin wins in Ukraine it will be a tragedy for the Ukrainians, but it will also send a very dangerous message to authoritarian leaders all over the world because then the message will be that when they use military force they can achieve their goals,” he said.

“The war in Ukraine matters for all of us, and therefore we’re also very grateful for the support that Japan is providing, using also the planes and the cargo capabilities,” Stoltenberg added.

Japanese Prime Minister Fumio Kishida has sounded alarm that Russia’s aggression in Europe could happen in Asia, where concerns are growing over China’s escalating tension with Taiwan as well as threats from North Korea.

Already a close ally of the United States, Japan has in recent years expanded its military ties with other Indo-Pacific nations as well as the United Kingdom, Europe and NATO. Japan was also quick to join the US-led economic sanctions against Russia, and the country has also provided humanitarian aid and non-combative defence equipment for the Ukrainians.

In a crucial break from its post-World War II principle that limited Japan to self-defence, Tokyo unveiled a new national security strategy in December that will see a large increase in its military capabilities, including the deployment of long-range missiles to preempt enemy attacks. Japan also hopes to further ease restrictions on arms export to strengthen the country’s feeble defence industry.

Stoltenberg is set to meet Kishida and hold a joint news conference later on Tuesday.

While in South Korea on Monday, Stoltenberg called for Seoul to provide direct military support to Ukraine. So far, Seoul has provided humanitarian aid and other support, citing a longstanding policy of not supplying weapons to countries in conflict.

Stoltenberg discussed with South Korean President Yoon Suk-yeol NATO’s possible role in dissuading North Korea from its growing nuclear ambitions following an unprecedented number of ballistic missile tests in 2022, Yoon’s office said. Stoltenberg also mentioned US intelligence reports accusing North Korea of providing weapons to Russia to support its war in Ukraine.

North Korea has condemned Stoltenberg’s visits to South Korea and Japan, saying NATO was trying to put its “military boots in the region” and attempting to pressure the US’s Asian allies into providing weapons to Kyiv.

Pyongyang has criticised increasing cooperation between NATO and US allies in Asia as a process to create an “Asian version of NATO”.