West Texas Intermediate crude surged more than five percent in early trade on Monday as traders grow increasingly worried about an energy crisis after Western nations imposed fresh sanctions on Moscow over its invasion of Ukraine.

The contract rose 5.07 percent to $96.23, while Brent crude was up 4.30 percent at $102.14.

The United States and European Union said they would exclude some Russian banks from the international SWIFT  payments system and personally targeted President Vladimir Putin and Foreign Minister Sergei Lavrov.

They also banned all transactions with Russia's central bank, sending the ruble crashing with Bloomberg saying it was indicated nearly 30 percent down in offshore trading Monday.

"Removing some Russian banks from SWIFT could result in a disruption of oil supplies as buyers and sellers try to figure out how to navigate the new rules," Andy Lipow, of Lipow Oil Associates in Houston, Texas, noted.

Traders will be closely watching a meeting this week of OPEC and other major producers led by Russia, where they will discuss plans for further output.

The group has agreed previously to increase production gradually each month, but the Ukraine crisis could throw those plans into disarray.

On Sunday, Ukraine said it had agreed to send a delegation to meet with Russian representatives on the border with Belarus, though Ukraine's President Volodymyr Zelensky said he was sceptical about the talks.