More than 500 tonnes of material from its programs to develop nuclear weapons to build missiles left Libya by ship on Saturday, headed for a secret location in the United States, National Security Council spokesman Sean McCormack said.

Such materials began arriving in the United States after Libyan leader Moamer Kadhafi made his surprise pledge on December 19, following nine months of secret talks with the United States and Britain, to quit his quest for weapons of mass destruction (WMD).

The White House said in late January that 25 tonnes of components and products to build such weapons had been brought by plane from Libya to the United States.

Late last month, Washington took giant steps closer to normalizing relations with Libya on Thursday by ending a two-decade travel ban, easing some economic sanctions and pushing for deeper diplomatic ties.

Washington rescinded a travel ban enforced since relations with Tripoli broke off in 1981, allowing US citizens to use their passports to travel to or through Libya and spend money there.

US President George W. Bush also authorized US firms with pre-sanction holdings in Libya to resume business there, and invited Tripoli to lay the groundwork for eventually normalizing relations by establishing a diplomatic interests section -- but not an embassy -- in Washington.

WAR.WIRE