South Korea has seized a Hong Kong-flagged vessel suspected of transferring oil to North Korea in defiance of international sanctions, a foreign ministry official said on Friday. The vessel, Lighthouse Winmore, transferred refined petroleum products to a North Korean ship in international waters in late October, the official told Reuters. The United States proposed blacklisting the Hong Kong-flagged ship to the U.N. Security Council for circumventing sanctions slapped on North Korea for its nuclear and missile programmes, documents seen by Reuters this month showed.