UN - Secretary-General Ban Ki-moon said on Wednesday that he's heading to West Africa to demonstrate the U.N.'s solidarity with the countries most affected by the Ebola outbreak, and to see for himself how the world is responding.The UN chief will leave on Wednesday night and visit hard-hit Liberia, Sierra Leone and Guinea as well as Mali. He will also visit Ghana, where the UN Mission for Ebola Emergency Response is headquartered."I want to see the response for myself and show my solidarity with those affected, and urge even greater global action," Ban told a news conference.In the world's largest Ebola outbreak, some 18 500 people have been infected, mainly in Liberia, Sierra Leone and Guinea. Of those, more than 6 800 have died.Ban said local communities and national governments are engaged, there has been “an impressive outpouring of life-saving contributions from across Africa and across the world... and we are beginning to see improvements”.But he said there is still a shortage of people and resources to tackle Ebola, and warned that "now is not the time to ease up on our efforts”."As long as there is one case of Ebola, the risk remains," Ban said. "We must do everything we can to get to zero."During his trip, Ban said he will meet with five presidents and staff from the UN mission known as UNMEER. He said he will also try to visit treatment facilities provided by key countries such as the US, Britain and France, and some other local treatment centres.The secretary-general said he will be travelling with Dr. Margaret Chan, the World Health Organization director-general, and UN Ebola chief Dr David Nabarro. He said Tony Banbury, who heads UNMEER and is in Conakry, will also join the trip.