Brent North Sea crude oil for May delivery reached $139.13 shortly after electronic trading opened around 2300 GMT, heading towards a 2008 record high before retreating slightly over the next hour.
The European benchmark crude hit its record price of $147.50 per barrel in July 2008.
By 0030 GMT, Brent crude had dropped a little more to $128.77 per barrel — 9.02% higher than its closing price on Friday.
The price per barrel of Brent oil has increased 33% since Russia invaded Ukraine on February 24.
New York’s benchmark West Texas Intermediate oil also soared Sunday to $130.50 per barrel for April delivery. It, too, then dropped slightly over the next hour and a half.
By 0030 GMT, WTI crude was at $125.15 per barrel, an 8.18% increase from its closing price on Friday.
US Secretary of State Antony Blinken said Sunday that Washington was in “active discussions” with European nations about banning Russian oil imports as further economic penalty against Moscow, although he stopped short of announcing an outright boycott.
Even if oil is technically still exempt from sanctions, Russian oil exporters are struggling to find buyers. Shell is one of the only companies still buying Russian oil, although it said it would donate the profits to Ukrainian causes.
Asked Sunday on CNN about Shell’s announcement, Ukrainian Foreign Minister Dmytro Kuleba urged Shell and other energy giants to cut off Moscow’s biggest revenue source and “stop buying Russian oil.”
“Russian oil and gas smells of Ukrainian blood,” he said.