Oil prices extended a bull run on May 31 after the EU agreed to a partial and phased ban on Russian oil and China decided to lift some coronavirus restrictions amid rising demand ahead of the peak U.S. and European summer driving season.

Brent crude for July, which expires on May 31, rose $2.11, or 1.7%, to $123.78 a barrel by 11:03 a.m. GMT, after earlier rising to $124.10 – its highest since March 9. The August contract rose $1.57 to $119.17.

The premium of August-loading Brent contracts over a six-month spread hit a nine-week high at close to $15 a barrel, indicating current supply tightness.

U.S. WTI crude was trading at $118.53 a barrel, up $3.46 in a fourth consecutive session of gains, up 3% from Friday's close, hitting its highest since March 9. There was no settlement on May 30 due to a U.S. public holiday.

Both July-loading contracts are set to end May as the sixth straight month of rising prices.

EU leaders agreed in principle to cut 90% of oil imports from Russia, the bloc's toughest sanction yet on Moscow since the invasion of Ukraine three months ago.

Once fully adopted, sanctions on crude oil will be phased in over six months and on refined products over eight months. The embargo exempts pipeline oil from Russia as a concession to Hungary.

"As two-thirds of the Russian crude oil exports are seaborne around 1.5 MMbbl/d of oil will need to be replaced by the EU," PVM analyst Tamas Varga said.

"This volume is actually closer to 2.1-2.2 MMbbl/d as both Poland and Germany are planning to phase out pipeline purchases by the end of the year."

On the production side, OPEC+ is set to stick to a modest July output hike of 432,000 bbl/d, six OPEC+ sources said.

Oil prices found further support as Shanghai has announced an end to its COVID-19 lockdown and will allow people in China's largest city to leave their homes and drive their cars from June 1.