The trip comes as South Korea signalled it could reverse a long-standing policy of not providing weapons to countries in conflict following revelations that North Korea had deployed thousands of troops to aid Russia's war efforts against Ukraine.

The Ukrainian defence ministry confirmed to AFP that defence chief Rustem Umerov is already in South Korea and that "his meetings there are taking place".

South Korean media had reported a planned meeting between Umerov and President Yoon Suk Yeol -- though the presidential office declined to confirm.

The Ukrainian delegation was expected to "share intelligence on North Korea's troop deployment to Russia" and seek Seoul's support for Kyiv's war efforts, South Korean Yonhap news agency reported, citing unnamed sources.

Ukrainian President Volodymyr Zelensky said in an interview with South Korean media last month that his country was preparing to submit a list of needed military support.

"This will be carried out simultaneously with our envoy, who will visit South Korea soon, and discussions will be held on weapons support," Zelensky said according to a transcript by KBS.

He added the list would include artillery support and air defence systems.

Earlier this month, Yoon said whether -- or how -- South Korea decides to help Ukraine directly depends on "the level of North Korean involvement" in the conflict, adding that Seoul was "not ruling out the possibility of providing weapons".

If South Korea were to supply arms, the initial batch would be defensive in nature, Yoon said.

Ukraine is reliant on Western air defence systems, particularly Patriots, to protect itself from Russian missile barrages -- and has been calling for more deliveries.

South Korea, which remains technically at war with the nuclear-armed North and has maintained production of weaponry long overlooked by Western arms industries, could make a significant impact if it decides to supply weapons, experts say.