The United States has begun withdrawing its peacekeeping troops from Liberia, ahead of the arrival of a United Nations force.
Most US forces did not come ashore
Two warships have already left Liberia waters, and a third is due to leave mid-week, defence officials said.
The UN is due to start deploying its largest force in the world - some 15,000 troops - on Wednesday.
About 100 US soldiers remain on the ground in Liberia, mainly stationed around the US embassy.
The US forces were sent to Liberia in August to support Nigerian-led peacekeepers who helped restore calm to the capital, Monrovia, after months of fighting between government troops and rebels.
However, the peacekeepers have not deployed to the rest of the country, where tension between the rival forces remains high.
Stretched by military commitments in Iraq and Afghanistan, President George W Bush said the American troops would be withdrawn by 1 October.
The US warships carried more than 4,000 sailors and Marines, but most of them never set foot on the mainland.
Two of the ships - the USS Carter Hall and the USS Nashville - left Liberian waters over the weekend.
The third vessel - the USS Iwo Jima - is expected to follow in the next few days.
"Since our mission was to facilitate Ecomil [West African peacekeeping forces] efforts to stabilise Monrovia and create conditions for humanitarian relief efforts to resume, that mission has been largely accomplished," said Pentagon spokesman Lieutenant Dan Hetlage.
The 3,500-strong Ecomil force will swap their green helmets for the blue of the UN peace force, Unmil, on Wednesday.
"The re-hatted West African troops will be joined within two weeks by a battalion from Bangladesh as Unmil steadily increases its strength over the coming months," Unmil said.
The BBC's West Africa correspondent Paul Welsh, who is in Monrovia, says the US warships, aircraft and surveillance abilities have been a real and a psychological help to the West African peacekeepers.
Liberia outside Monrovia remains highly unstable
But, he says, many in Monrovia, including the charity Oxfam, believe the pullout of the Americans before the full deployment of the UN force puts the peace in jeopardy.
Businessman Gyude Bryant is due to take over as interim president on 14 October, heading an administration including both government and rebel representatives.
The power-sharing authority is tasked with organising elections in 2004.