South Korea and Ukraine agreed Wednesday to deepen security cooperation in response to the "threat" posed by the deployment of North Korea troops in Russia, the presidency in Seoul announced.

The statement followed a meeting between South Korea's president and Ukraine's defence minister after their countries sounded the alarm over the deployment of thousands of Pyongyang's troops in western Russia.

South Korean President Yoon Suk Yeol met with Defence Minister Rustem Umerov and "expressed hope that South Korea and Ukraine would work together to devise effective measures to address security threats posed by North Korea's military cooperation with Russia", the presidency said. 

"Both sides agreed to continue sharing information on North Korea's troop deployment to Russia and the transfer of weapons and technology between Russia and North Korea," the presidency added.

The trip came after South Korea signalled it could reverse a long-standing policy of not providing weapons to countries in conflict but there was no mention of arms supplies in the statement.

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

He added that 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.