U.S. President Joe Biden has warned Israel against attacking Iran’s nuclear sites, and U.S. officials worry a strike on its energy infrastructure could roil energy markets.

But with Israeli retaliation against Iran expected at any time, the U.S. is finding it has few assurances against further escalation.

Biden’s team is pressing Israel to limit its retaliation against Iran for a strike last week to military targets such as air bases and missile sites.