Washington: There are still up to half a million displaced persons in Ivory Coast, the United States has said, a sharp increase over a United Nations (UN) report the day before that put the number at just over 300,000.

"The situation in Cote d'Ivoire is improving, but some continuing unrest is still generating new refugees," US State Department spokesman Mark Toner said on Wednesday.

Toner said that fear among those who have already fled kept "the majority of refugees from returning home at the present time.

"Up to an estimated 500,000 remain internally displaced," he said, adding that in total some 210,000 people fled across the border since November, and another one million people were internally displaced.

On Tuesday, the UN High Commissioner for Refugees said it and its partners had registered 322,277 internally displaced people, with most of those in the west, north and in the economic capital of Abidjan.

Toner also said that the US would give an additional USD 7.5 million in aid to the country, bringing to more than USD 51 million the assistance that the Obama administration has given Ivory Coast during its post-election crisis.

For five months, former president Laurent Gbagbo refused to step down despite an UN-backed election commission's ruling that he had lost the November Presidential elections.

The winner, Alassane Ouattara, was finally sworn in as President on May 21.