NATO Secretary-General Jens Stoltenberg urged South Korea on Monday to increase military support to Ukraine, citing other countries that have changed their policy of not providing weapons to countries in conflict after Russia's invasion.

Stoltenberg is in Seoul, the first stop on a trip that will include Japan and is aimed at strengthening ties with U.S. allies in the face of the war in Ukraine and rising competition with China.

Speaking at the Chey Institute for Advanced Studies in Seoul, he thanked South Korea for its nonlethal aid to Ukraine, but urged it to do more, adding there is an "urgent need" for ammunition. Russia calls the invasion a "special operation."