The US has a moral duty to intervene in Liberia's civil war because it helped to found the West African nation, the archbishop of Monrovia said yesterday.

"The US has a moral obligation to intervene in Liberia. It's their moral duty. We are really disappointed that the US doesn't do anything for us," Archbishop Michael Francis told reporters.

Liberia, Black Africa's first independent country, was set up by freed American slaves with backing from the US government in the early 19th century.

Francis, who is also the president of the Inter-Religious Council of Liberia - which has played a leading role in earlier peace talks between rebels and President Charles Taylor – said Washington could put an end to the war quickly, if it so wished.

"You put 500 (US) marines in Liberia and this war will be finished," he said, adding that former colonial rulers had been more active in their troubled ex-colonies in the region when they were in crisis.

"We have no one to stand up for us: the British have gone to Sierra Leone, and the French have committed themselves in Ivory Coast," he said.

The current war has displaced thousands of Liberians since it started up in 1999, and both rebel and government forces are accused of widespread rights abuses including murder, torture, rape and enrolling child fighters.

The Liberians United for Reconciliation and Democracy (Lurd) main rebel group and the newly emerged Movement for Democracy in Liberia (Model) together control 12 of Liberia's 15 counties.

Lurd fighters advancing on the capital had pulled back to the outskirts of Monrovia on Wednesday after the rebels and the government agreed to a truce in principle.

But the ceasefire has yet to be signed, with peace talks in nearby Ghana at a standstill and the belligerents accusing each other of renewing hostilities.

Up to one million people are estimated to be living rough in Monrovia, where there is an acute shortage of food, potable water, medicines and social services.

The current war comes only two years after another bloody seven-year conflict, in which Taylor was a key player and initiator.

In the early 19th century, the American Colonization Society, a private US organisation, was given a charter by the US government to establish a settlement for freed slaves on Africa's west coast.

Under president James Monroe, the US government provided funds and supported negotiations over the ceding of land to the settlers.

The first settlers landed at the site of Monrovia in 1822 and united to form the Commonwealth of Liberia in 1938, under a governor appointed by the Colonization Society. – Sapa-AFP.