The United States ambassador to the United Nations is on her way to visit all three of the West African countries hit hardest by the Ebola outbreak, amid rising calls for travel restrictions back home in the U.S.

Samantha Power will visit Liberia, Sierra Leone and Guinea "to draw attention to the need for increased support for the international response," said a statement released late Saturday by the U.S. mission.

A spokesman said Power had already departed and was set to land in the capital of Guinea, Conakry, on Sunday. Earlier Saturday, the ambassador tweeted a photo of herself with Guinea's ambassador to the United Nations.

The United Nations has repeatedly called for a greater international response to the worst-ever outbreak of the deadly disease, which has killed more than 4,900 people. The U.N. mission to counter Ebola is the first time the world body has set up such an effort in response to a public health crisis.

Power has been vocal about the need for a stronger global response to Ebola's devastating spread. In a speech a week ago, she even praised Cuba, a country that has been under a U.S. embargo for decades, for having sent 165 doctors to Sierra Leone.

"The international community isn't just losing the race to Ebola. We are getting lapped," she said in the speech.

The U.N. repeatedly has expressed concern as airlines and shipping companies cut service to the three most affected countries, making it difficult to deliver aid workers and supplies and causing food prices to soar. Aid workers with the U.N. and elsewhere also have worried openly about the challenges of attracting trained volunteers to come and help out.

The U.S. statement said Power will visit national Ebola coordination centers and meet with U.S. and U.N. personnel on the ground in the Ebola-affected region. That will include workers with the Centers for Disease Control and Prevention and the defense department. She'll also meet with government officials and civil society workers.

The statement did not say whether Power would meet with survivors of the outbreak.

Power also will visit Ghana, the headquarters for the U.N.'s Ebola mission, and Belgium.

The ambassador's trip was announced shortly after new quarantine policies were put into effect in New York as authorities reacted to the infection of a doctor who had been treating Ebola patients in Guinea. The governors of New York, New Jersey and Illinois on Friday declared mandatory 21-day quarantines for arriving travelers who have had contact with Ebola patients in West Africa.

Power flew out of Washington on her way to West Africa. Spokesmen for the U.S. mission did not immediately say whether the ambassador would return through Washington and what precautious she would take while in the Ebola-hit countries.

The U.S. has pledged to send up to 4,000 troops to build treatment units and to train health care workers in the worst-hit region. Obama on Wednesday said the U.S. so far had 100 workers from the CDC and 500 military personnel in West Africa.