South Korea is not ruling out providing weapons directly to Ukraine, President Yoon Suk-yeol has said, following North Korea’s deployment of troops to support Russia in its war.

Pyongyang’s involvement in the conflict presented a threat to Seoul, as the reclusive state’s soldiers get much-needed combat experience, which its military lacks, and additionally gets rewarded by Moscow with sensitive military technology transfers, Yoon told a news conference on Thursday.

South Korea, a major arms exporter, has a longstanding policy of not providing weapons to countries in conflict.

“Now, depending on the level of North Korean involvement, we will gradually adjust our support strategy in phases,” Yoon said.

“This means we are not ruling out the possibility of providing weapons.”

Yoon said he discussed North Korea with United States president-elect Donald Trump in a phone conversation that laid the groundwork for a face-to-face meeting in the “near future”.

North Korea has become one of the most vocal and important backers of Russia’s war in Ukraine.

South Korea and the West have long accused Pyongyang of supplying artillery shells and missiles to Moscow for use in Ukraine.

But intelligence reports from Seoul, Washington and NATO have revealed that North Korea has deployed 10,000 troops to Russia, indicating an even deeper involvement in the conflict.

Yoon said his office would monitor the unfolding developments related to the operations of North Korean soldiers, and if he decided to provide weapons to Ukraine, the initial batch would be defensive.

“If we proceed with weapons support, we would prioritise defensive weapons as a first consideration,” he said, without elaborating.

Ukrainian Defence Minister Rustem Umerov told South Korean broadcaster KBS that the Ukrainian military had its first confrontation with North Korean soldiers.

Ukrainian President Volodymyr Zelenskyy, who has criticised the West’s lack of response to the arrival of the North Korean soldiers on the front lines, said these “first battles with North Korea open a new chapter of instability in the world”.

South Korea supplies weapons to Poland, including rocket launchers, tanks and FA-50 fighter aircraft.

In a defence exhibition in Seoul in October 2023, Yoon said that he wants his country to become the “world’s fourth-largest defence equipment exporter”.

Compared with his dovish predecessor Moon Jae-in, Yoon has taken a tough stance with the nuclear-armed North while improving ties with security ally Washington.

Since North Korean leader Kim Jong Un’s second summit with then-president Trump collapsed in Hanoi in 2019, Pyongyang has abandoned diplomacy, doubling down on weapons development and rejecting Washington’s offers of talks.

While in office, Trump met with Kim three times, beginning with a landmark summit in Singapore in June 2018, though the pair failed to make much progress on efforts to denuclearise the North.

Trump has previously accused South Korea of getting a “free ride” on US military power and demanded it pay far more of the cost of keeping US troops in the country to counter the threat of aggression by North Korea.

On Monday, a day before the US election, South Korea and the US signed a five-year plan under which Seoul agreed to an 8.3 percent jump in its 2026 contribution to the cost of maintaining US bases in the country to 1.52 trillion won ($1.09bn), with future increases capped at 5 percent.

Yoon on Thursday said: “We will be building a perfect security posture together with the new administration in Washington and safeguard our freedom and peace.”

On Wednesday, the Federation Council of Russia, the upper house of parliament, ratified a landmark mutual defence pact with North Korea. The treaty was signed in Pyongyang on June 19 during a state visit by Russian President Vladimir Putin.

The unanimous vote in the upper house formalises months of increasing security cooperation between the two nations, the largest since the time they were communist allies during the Cold War.