West Texas Intermediate and Brent crudes declined on speculation that Crimea’s vote to leave Ukraine and join Russia is unlikely to disrupt oil shipments.

WTI fell as much as 0.8 percent, while Brent tumbled 1.1 percent. The U.S. and the European Union warned Russia not to annex Crimea after the referendum, setting the stage for sanctions against the world’s biggest energy-producing country. Brent, which is used to price more than half of the world’s crude and, unlike WTI, can be exported, is often more sensitive to changes in the global supply-and-demand balance.

“We’re not anticipating sanctions on Russia to include a halt of oil or gas purchases,” said Addison Armstrong, director of market research at Tradition Energy in Stamford, Connecticut. “With Europe dependent on Russian exports of oil and gas and Russia depending on the earnings they provide, the market at this stage isn’t anticipating a disruption.”

West Texas Intermediate for April delivery dropped 33 cents, or 0.3 percent, to $98.56 a barrel at 10:44 a.m. on the New York Mercantile Exchange. The volume of all futures traded was 4.4 percent above the 100-day average.

Brent for May settlement fell 95 cents, or 0.9 percent, to $107.26 a barrel on the London-based ICE Futures Europe exchange. Trading volume was 48 percent lower than the 100-day average. The April contract expired on March 14. Brent traded at a $9.14 premium to May WTI contract.