Headed by Donald Mahley, the US State Department's special negotiator for chemical and biological arms control issues, the US-British team of about a dozen experts was in Tripoli planning how to destroy tons of mustard gas and how to evacuate any higly enriched uranium from Libya, a senior US official told the daily.

The illicit materials, the senior official said, would likely be shipped to a secure facility in Britain or the United States.

Mohamed ElBaradei, head of the International Atomic Energy Agency (IAEA), met Monday in Vienna with US Under Secretary of State for Arms Control and International Security John Bolton and British envoy William Ehrman to discuss aspects of Libya's voluntary atomic disarmament.

The three officials agreed to let the UN nuclear watchdog oversee Libya's atomic disarmament, but for US and British experts to carry out the removal and destruction of equipment, the IAEA chief said.

The officials spoke to reporters after the meeting in the Austrian capital, but did not mention the arrival in Tripoli of the joint US-British team.

IAEA, US and British weapons inspectors have all been to Libya since Tripoli announced the shift in mid-December following months of secret negotiations between Tripoli, London and Washington.

A Western official told The New York Times that US officials were considering opening an office in Tripoli to facilitate the work of weapons experts and to serve as a channel for direct diplomatic contact between Libyan and US officials.

The senior US official also said Libya would probably extend the deadline for the remainder of the compensation payments it agreed to make to the families of the victims of the 1988 Lockerbie tragedy.

Libya was under international sanctions for years over the December 1988 bombing of PanAm flight 103 a US airliner over the Scottish town of Lockerbie that killed 270 people.

The United Nations lifted its embargo in September after Tripoli agreed to pay 2.7 billion dollars in compensation and accept responsibility for the bombing. That followed the conviction of a former Libyan intelligence agent for the bombing.

US sanctions remain in place however.

Libya so far has paid four million dollars to each family of the Lockerbie victims. But under the terms of the agreement, it may forgo outstanding compensation payments of six million dollars if US sanctions are not lifted by May 12.

Libya recently reminded Washington that the four-million-dollar-per-family payments would not be made if the US Congress did not act to lift US sanctions on Libya by May.

The State Department responded earlier this month by saying that US sanctions on Libya would not be lifted until Tripoli met the disarmament requirements for their removal and not before.

The senior official told The New York Times that if it appeared by May that both the disarmament tasks and action by the US Congress appeared to occur, Libya would probably extend the period of payment.

WAR.WIRE