Yemen’s Houthi military-political movement announced on Monday the imposition of a naval blockade on Saudi Arabia. This move opens a new front against the United States in the context of its war with Iran and expands the threat to global energy supplies and world trade beyond the Persian Gulf, Reuters reports.

An official statement by the Houthi armed forces said they were declaring a “naval embargo against the criminal Saudi enemy on the principle of ‘an eye for an eye,’ effective immediately...”

Representatives of the movement said the decision was a response to the “unjust and cruel siege” imposed by Saudi Arabia on Yemen.

There has so far been no official response from Saudi Arabia.

A complete closure of the Bab el-Mandeb Strait could reduce global oil supply by 7%, as it would block most routes for Saudi oil exports from the region. This would worsen the already massive disruption to global oil flows caused by the war in the Persian Gulf, which has already led to a 10% drop in world supplies.