US AV-8B Harrier jets and Super Cobra attack helicopters based on amphibious warships off the coast will provide cover for the transfer of the port area from rebel forces to the ECOMIL peacekeeping force, the officials said.

Lieutenant General Norton Schwartz, operations director of the Joint Staff, said the US troops will include a 150-strong rapid reaction force that will be deployed on land as well as Navy SEAL commandos, engineers and and Marine liaison troops embedded with the West African force.

"The mission hasn't changed," said Lawrence Di Rita, the Pentagon's acting spokesman.

Di Rita and Schwartz portrayed the operation as a limited effort to back up the West AFricans until a second battalion of peacekeepers arrive, control is established over the port area and humanitarian relief operations get started.

US helicopters might be used to ferry the peacekeepers from the airport to the port area, under an aerial escort by US attack helicopters and Harriers, they said.

"Aerial escort would provide overwatch of the movement of the ECOMIL forces from the airport to the port and could include fixed-wing aircraft like Harriers or rotary-wing aircraft, for example, Hueys or Cobra helicopters," said Schwartz.

The US rapid reaction force will be kept on land at least until the second peacekeeping battalion has deployed, the officials said. But Di Rita acknowledged that plan was "subject to change."

Liberians United for Reconciliation and Democracy, the rebel group holding the port area, has agreed to withdraw at noon Thursday and surrender the area to the ECOMIL peacekeeping force. But looting already has broken out in the port area.

General Festus Okonkwo, the Nigerian commander, "will determine the appropriate time for the movement to the port to occur, and we will provide the assistance necessary to see that he can accomplish that," Schwartz said.

US Navy SEALs on Wednesday began a preliminary survey of the waterways of the port area to ensure the are clear of obstacles so that a UN ship carrying food and fuel can enter.

Military engineers also will conduct an assessment of the port conditions to see what will be needed to get humanitarian aid flowingo the country.

The estimated 200 US troops slated for deployment will join about 100 others already on the ground.

So far, 746 West AFrican peacekeepers have deployed under the command of a Nigerian general. The second battalion was expected to begin deploying at the end of the week, the officials said.

WAR.WIRE