The World Health Organisation is set to hold emergency talks to discuss the Ebola epidemic, the BBC reports.
The meeting will assess the efforts so far to control the virus, which continues to spread in the worst affected countries in West Africa.
New rules in the US require travellers from Liberia, Guinea and Sierra Leone to arrive at one of five airports.
Meanwhile a curfew has been imposed in a town in Sierra Leone after two people were shot dead in riots on Tuesday.
The current outbreak of the virus has already killed more than 4,500 people – mostly in Guinea, Liberia and Sierra Leone.
