Hungary maintained its veto on Monday on new EU sanctions on Russia and a huge loan for Ukraine amid a dispute over oil supplies, in a blow to Europe's pro-Ukrainian consensus on the eve of the war's fourth anniversary.

On the ground in Ukraine, Kyiv claimed a rare front line advance, though Moscow continued its campaign of targeting Ukrainian cities, killing two people in drone strikes in the south.

The diplomatic spotlight was on Brussels, where European foreign ministers tried unsuccessfully to persuade Budapest not to ?punish Ukraine for delays restarting the flow of Russian oil to Hungary via a Soviet-era pipeline.