At the outskirts of a South Korean industrial city, workers at a sprawling weapons factory were conducting final-stage testing for a newly built surface-to-air defense system that could, eventually, head to Ukraine.

Longstanding domestic policy bars Seoul from sending weapons into active conflict zones, but ever since its spy agency accused the nuclear-armed North last month of sending thousands of soldiers to help Moscow fight Kyiv, South Korea has warned it might change course.

If so, likely top of the list for Ukraine would be the "Cheongung" — or Sky Arrow — air defense system, a domestically produced Iron Dome-style interception shield that AFP saw Thursday during an exclusive tour of the Hanwha Aerospace factory in the southern city of Changwon.