National Security Adviser Chang Ho-jin said on Sunday that the mix of South Korea's arms support for Ukraine will vary depending on how Russia's military cooperation with North Korea goes.

Appearing on a KBS program on Sunday, Chang stressed that Seoul's decision on whether to provide weapons to Ukraine depends on Russia. 

The security adviser rhetorically asked if there would be any line remaining for South Korea if Russia gave precision weapons to North Korea, hinting that South Korea could provide lethal weapons to Ukraine if Russia crossed the line.

On Thursday, Chang said that the top office will reconsider providing arms support to Ukraine after Russian President Vladimir Putin and North Korean leader Kim Jong-un signed a comprehensive strategic partnership treaty that includes a vow of mutual aid if either country is attacked.

Later that day, Putin warned that it would be a "big mistake" if South Korea supplied weapons to Ukraine.

As for future relations between South Korea and Russia, Chang said that not only South Korea but also Russia should make efforts to improve bilateral relations, adding that if Moscow wants to restore and develop relations with Seoul after the Ukraine war ends, Russia should think carefully.