The wreckage will be melted down Tuesday to form the front of the bow of the 196 meter (684-foot) amphibious assault craft due to be delivered to the navy in 2007, said the ship's builders, Los Angeles-based Northrop Grumman.

"The metal will be melted down and cast into the bow stem of the ship in a tribute to the victims and the heroes of 9/11 as well as to the courage of the New York people after the attacks," said company spokesman Ed Winter.

Some 2,792 people died when two aircraft were flown into the twin towers on September 11, 2001, causing an inferno that triggered the skyscrapers' collapse in the worst terror strike in history.

Part of the twisted frame of the building was shipped to the southern US city Amite, Louisiana, where a ceremony marking the melting will be held at a foundry on Tuesday.

The state-of-the-art ship, to carry around 800 marines and equipment including helicopters, will be built by Northrop Grumman's ship systems division in nearby New Orleans.

"It is a fitting tribute that the steel will be cast into the part of the ship that will slice through the water, representing the toughness and resilience of the people of New York," said company official Bill Glenn.

"It is the part of the ship that will lead the ship into the future," he added.

The symbolic use of part of the World Trade Center comes just days ahead of the second anniversary of the attacks on the US East Coast that transformed the country.

WAR.WIRE