The Caribbean island of St. Lucia on Wednesday ordered a ban on allowing in people travelling from West African nations hit by the deadliest outbreak of the Ebola virus. Farther south, Colombia too announced a similar ban later Wednesday.

Kenny Anthony, the prime minister of St. Lucia, said that the country will not allow people arriving from Sierra Leone, Guinea and Liberia, until the outbreak is brought under control, according to Associated Press, or AP. Anthony added that the move will reduce the risk of the disease being brought into the country by an infected traveler. Colombia’s foreign ministry reportedly said in a statement that it would also ban travelers from Guinea, Liberia, Sierra Leone, Nigeria and Senegal.

Anthony had said Wednesday, according to AP, that St. Lucia does not have the capacity "to manage any crisis that lands on our doorstep, any crisis of that kind,” adding that passengers from Nigeria will need to show a recent medical certificate stating they are Ebola-free before they are allowed into the island nation.

Haiti Prime Minister Laurent Lamothe also said, in a tweet, that the U.N.'s peacekeeping force in the country would suspend the rotation of troops from African countries, as a preventative measure.

There is a growing fear among the general public and governments that Ebola could transform into a pandemic after several missteps by health authorities, including in the U.S., have come to light in recent weeks.

The measures initiated by these governments followed an announcement from the U.S. on Wednesday that yet another nurse in a Dallas hospital had tested positive for the Ebola virus, which has killed over 4,000 and infected more than 8,000 people, mostly in West Africa. Amber Joy Vinson became the second person to contract the virus on American soil after treating Thomas Eric Duncan who died from the virus at the Texas Health Presbyterian hospital in Dallas.

U.S. President Barack Obama has called for more collaboration among the international community to counter the virus' spread and the U.S. has so far pledged about $142 million to Liberia, where over 2,300 people have died from the disease.

"We are going to have to make sure that we do not lose sight of the importance of the international response to what is taking place in West Africa," Obama said Wednesday, according to Agence France-Presse, adding: "Leaders agreed that this was the most serious international public health emergency in recent years and that the international community needed to do much more and faster."

Airports in the U.S., U.K., and Canada have started screening people at their airports as a precautionary measure.