The presidential office has denied media reports that South Korea is looking to first send ammunition, such as 155mm artillery shells or anti-tank guided missiles, to Ukraine as part of its speculated arms provision.

A presidential official said Friday that details on the potential arms supply would be reviewed in accordance with Russia's response to South Korea's position on the issue, adding that various plans could be considered in weapons support.

On Thursday, a high-ranking official at the top office said Seoul would review its existing policy of not supplying lethal weapons to Ukraine after North Korea and Russia signed a treaty to mutually provide immediate military assistance if either side is attacked.

The official said it will be "interesting" for Moscow to find out little by little what Seoul will do, but declined to comment on whether arms supply to Kyiv would involve lethal weapons.

Speaking at a press conference in Vietnam on Thursday, Russian President Vladimir Putin warned South Korea that sending weapons to Ukraine would be a "very big mistake."