International development organisation Plan International says the outbreak of the Ebola virus is a "health crisis with global dimensions".
Dr Unni Krishnan, the body's head of disaster preparedness and response, said: "The arrival of Ebola in the most populous city in Africa is a wake-up call."
Ebola is no longer a regional crisis - it has become a health crisis with global dimensions. The international community needs to act now before it is too late.
The countries battling Ebola are among the poorest in the world and the public health systems across West Africa are fragile. The impacted countries desperately need financial and technical assistance to avoid a catastrophic situation.
More than 160 staff will work in a UK-funded facility in Sierra Leone which is due to open in October.
UK trials of a vaccine for the Ebola virus began today - but some experts complain that the response has been a long time coming.
A Swansea doctor who took leave to treat Ebola patients in Africa, is back on the wards after three weeks in isolation.