US officials said the opening of Umm Qasr followed dredging to clear wreckage, most of which has lain at the bottom of the port since the 1980-88 Iran Iraq war.

Umm Qasr has been receiving some humanitarian shipments since March, delivered by small vessels.

Its reopening came two weeks after the Coalition Provisional Authority, the US-led interim civilian administration in Iraq, suspended tariffs and trade restrictions on most goods going into or out of the country. The tariff holiday, which will last until the end of this year, effectively makes Iraq a free-trade zone, and is intended to revive an economy beleaguered by years of sanctions and state management.