Chevron Corp. has made no “fundamental changes” to its shipping routes even as Houthi attacks ratchet up in the Red Sea, a vital artery of global trade, chief executive officer Mike Wirth said January 16.

The California-based oil giant is working with naval authorities in the U.S. and Middle East to move its cargoes through the region, Wirth said in an interview with Bloomberg TV during the World Economic Forum in Davos, Switzerland. Shell Plc suspended all shipments through the Red Sea indefinitely after recent U.S. and U.K. strikes on Houthi rebels raised fears of escalated armed conflict, the Wall Street Journal reported earlier.

“On every voyage, we have a security plan, and it’s really ship by ship that we evaluate the situation,” Wirth said. “We have not made fundamental changes to how we’ve been moving ships over the last few weeks.”

Read more: UN Security Council Demands End to Red Sea Houthi Attacks

Wirth is “surprised” that the conflict in the Middle East hasn’t yet led to a significant rise in oil prices. Stronger U.S. shale production has so far helped offset such fears, but any blockade in the Persian Gulf, a key outlet for OPEC crude, may lead to a “significant supply shortfall which could really impact markets,” he said.

Two Chevron ships were attacked by the Iranian navy in 2023, including one that was boarded and hijacked.

“The risks in that part of the world are very dynamic and volatile right now,” Wirth said.