Brent crude futures gained 46 cents, or 0.4%, to $119.89 a barrel at 0111 GMT, while U.S. West Texas Intermediate (WTI) crude futures jumped 60 cents, or 0.5%, to $115.67 a barrel, extending solid gains from last week.
"I don't think it would be a stretch to assume that speculators are positioning for a post-EU summit oil market bounce," said SPI Asset Management managing partner Stephen Innes.
Any further ban on Russian oil would tighten a crude market already strained for supply amid rising demand for gasoline, diesel and jet fuel ahead of the peak summer demand season in the United States and Europe.
EU governments failed to agree on an embargo on Russian oil on Sunday, but will continue talks on a deal to ban seaborne deliveries of Russian oil while allowing deliveries by pipeline, ahead of the summit on Monday afternoon, officials said.
If agreed, a deal would allow Hungary, Slovakia and Czechia to continue to receive their Russian oil via the Druzhba pipeline for some time until alternative supplies can be arranged.
EUnderscoring market tightness, the Organization of the Petroleum Exporting Countries and allies including Russia, together called OPEC+, are set to rebuff Western calls to speed up their oil output additions when they meet on Thursday. They will stick to their plan to add 432,000 barrels per day in July, six OPEC+ sources told Reuters.
