The United Arab Emirates has opened its first jetty outside the Persian Gulf that is capable of loading oil onto some of the world's biggest tanker ships.

The launch of the new $650 million facility in the eastern city of Fujairah on Wednesday will make it easier for hulking tanker ships known as "very large crude carriers" to load their cargo rather than have it ferried to them out at sea.

Docking at Fujairah's Indian Ocean-facing port means the tankers will not have to sail through and back out the narrow Strait of Hormuz at the mouth of the Gulf.

Fujairah is the terminus of a pipeline opened in 2012 that bypasses the Strait of Hormuz, which nearby Iran has in the past threatened to close.