Zelensky: At least 3K North Korean troops killed or wounded in Russia's war with Ukraine

"There are risks of North Korea sending additional soldiers and military equipment to the Russian army," Zelensky posted on Telegram following a briefing by Gen. Oleksandr Syrskyi, his top commander.

Russia reportedly sent roughly 12,000 North Korean troops since early August to aid its effort to rid Ukrainian forces in Kursk Oblast, where reports originated in November of foreign troops fighting with Russian soldiers.

Meanwhile, Seoul expects Pyongyang to send more of its troops and military equipment to Russia, South Korea's Yonhap news agency reported Monday. Zelensky vowed that Ukraine will have "tangible responses" to this, he added after the briefing.

Officials pointed to purportedly fabricated Russian military identity cards on dead North Korean soldiers as a way to conceal their nation-of-origin since Russia's escalation by importing troops from a neighboring country.

This arrived after top diplomats in the United States, Canada, France, Italy, Germany, the European Union, Britain, Australia, New Zealand, Japan and the Republic of Korea days ago blasted North Korea for cooperating with Russia's war, calling it a "dangerous expansion of the conflict" as Ukraine claimed dozens of DPRK troops were killed in battle.

Zelensky, meanwhile, issued warnings of the worldwide risk of a deepening of military ties between Pyongyang and Moscow that include a transfer of military weapons and other technology between the two allied communist nations.

The Main Directorate of Intelligence of the Ukrainian Defense Ministry previously reported "significant casualties" of North Korean troops. On Monday, Ukrainian special forces claimed to have inflicted more than 100 casualties over three days, ABC News reported.

American, Ukrainian and South Korean officials all have previously confirmed currently up to 12,000 North Korean soldiers were stationed inside Russia.

But while North Korean infantry tactics have been compared to ones used at least 70 years ago during the Korean War, there's also "some" signs that North Korea is taking steps to manufacture and supply suicide drones, a South Korean official told Yonhap.

However, suicide drones are but one goal that North Korean leader Kim Jong Un has been focused on, South Korean officials say.

"North Korea is preparing to rotate or increase the deployment of troops [in Russia], while currently supplying 240mm rocket launchers and 170mm self-propelled artillery," stated the South Korean Joint Chiefs of Staff.