The first person diagnosed with Ebola in the United States, Thomas Eric Duncan, has died in a Dallas hospital.
Mr Duncan became ill with the haemorrhagic fever after arriving in the Texas city from Liberia on 20 September to visit family.
Mr Duncan was being kept in isolation and receiving experimental drugs, the BBC reports.
Nearly 4000 people have died and thousands more are infected, mostly in West Africa, in the worst Ebola outbreak yet.
The news came shortly after US Secretary of State John Kerry urged all nations to boost their response to combat the virus and Britain announced it will send 750 troops to Sierra Leone to help build a treatment centre.
Mr Duncan, who worked as a driver for a courier company, tested positive in Dallas, Texas, on 30 September, 10 days after arriving on a flight from Monrovia via Brussels.
He became ill a few days after arriving in the US, but after going to hospital and telling them he had been to Liberia he was sent home with antibiotics.
Four days later, he was placed in isolation but his condition continued to worsen and this week he was given an experimental drug. Ten people he came into contact with are being monitored for symptoms.
Following Mr Duncan's diagnosis, the first case of contagion outside that continent was confirmed in Spain, where a nurse who treated an Ebola victim in Madrid contracted the virus herself.
UN updates Ebola death toll
The World Health Organisation has updated the toll from the Ebola epidemic in West Africa. It said the outbreak has killed 3,879 people out of 8000 cases, and there is no evidence the epidemic is being brought under control.
The WHO said Liberia and Sierra Leone, the two worst-hit countries, still only have 21 percent and 26 percent of the bed spaces they need, and neighbouring countries had been told to prepare for Ebola to spread across their borders.
The World Medical Association is the latest global organisation to issue a plea to all countries to do much more to stop the spread of Ebola.
President Margaret Mungherera told Radio New Zealand's Nine to Noon programme the biggest problem in the fight against Ebola in West Africa is not having enough available medical people or equipment.