Liberia's president is lifting a state of emergency imposed to control an Ebola outbreak that has ravaged the country and two other West African nations.

In a nationwide address on Thursday, President Ellen Johnson Sirleaf said that the move does not mean the outbreak is over, but that enough progress has been made to lift emergency measures.

Those measures closed schools, banned large public gatherings, shut some markets and allowed the government to restrict people's movements. Schools remain closed, but officials are discussing how and when to reopen them.

Liberia is seeing infections fall in some areas, although other hot spots are popping up.

Sirleaf announced the emergency regime on August 6, speaking of "a clear and present danger" from Ebola, which at the time had claimed around 1,000 lives across west Africa.

Parliament had been due to discuss extending the order, originally envisaged as a three-month measure, before Sirleaf's intervention.

Sirleaf said the relaxation was "not because the fight against Ebola is over" but because recent successes in battling the epidemic had combined "to reposition our efforts to sustain our fight against the virus".

She added that Liberia had acted "decisively" by imposing tough new regulations on closing borders, imposing curfews and quarantines, shutting schools and restricting public gatherings.

"As the virus progressed, posing a clear danger to the state, our neighbours and the rest of the world, we were compelled to declare a state of emergency," she said.

"We took on a fight, we appealed to the world, we appealed to our citizens, our citizens listened, and the world responded. Today we can all be proud of the progress."

Official figures show Ebola has claimed more than 5,100 lives across west Africa -- 2,836 of them in hardest-hit Liberia -- with the real death toll thought to be up to three times higher.

But the Liberian government said this week new cases had dropped from a daily peak of more than 500 to around 50, confirming tentative announcements by experts worldwide of an apparent slowdown.

The U.S/ military has scaled back plans for its Ebola mission in Monrovia, and will deploy a maximum of 3,000 troops instead of 4,000, it said on Wednesday.

Sirleaf reminded listeners however that while the overall picture was hopeful, hotspots were still springing up in rural areas, and a large number of people were still dying.

"We cannot let down our guard, nor can we afford to reduce our vigilance," she said, announcing that a curfew would remain in place but had been eased by one hour, with people required to be indoors by midnight.

Schools were due to open in September, but pupils across the country have had no lessons since the start of the summer holiday in July.

Classrooms would reopen "at the time that will be decided by the progress that we make in this fight", Sirleaf said, with local authorities consulted and pupils enlisted in cleaning up neglected premises.