MONROVIA, Liberia -- Liberia's president called Wednesday on the world to do more to end a spiraling Ebola outbreak, saying "Liberia cannot defeat Ebola alone."

U.S. President Barrack Obama announced Tuesday that he will order 3,000 military personnel to West Africa to help contain the dreaded disease, which has killed at least 2,400 people. The U.S. is also planning on delivering 17 treatment centres with 100 beds each to Liberia, which has been hardest hit by the outbreak.

President Ellen Johnson Sirleaf on Wednesday called that commitment significant but said she hopes it will only be the beginning.

"We hope this decision by the United States will spur the rest of the international community into action," she said in a written statement read out by Information Minister Lewis Brown at a press conference. "This disease is not simply a Liberian or West African problem. The entire community of nations has a stake in ending this crisis."

An Ebola outbreak in West Africa has also touched Guinea, Sierra Leone, Senegal and Nigeria, and is believed to have sickened nearly 5,000 people.

It is the largest Ebola outbreak ever, and public health experts have said the three hardest hit countries -- Liberia, Sierra Leone and Guinea -- are desperately short of everything needed to contain it, from health workers to the hazard suits needed to protect them.

In recent weeks, promises of aid have ramped up significantly, and Sirleaf praised Obama's commitment, which is among the biggest from any single country. Liberia was founded by former American slaves, and the two countries share close ties.

But even as she welcomed the aid, Sirleaf noted that the plans have to be formalized. American officials expect to have the first treatment centres open in a few weeks, and it is unclear when all of the personnel and equipment will be on the ground.

Public health officials have warned that the window is closing to stamp out the outbreak and that promises must be converted into action quickly.

Australia announced Wednesday that it is providing another $6.4 million to the fight. The U.N. has estimated it will cost $1 billion to contain Ebola.

Germany is also considering providing a mobile hospital to Liberia and may also send transport planes to help with logistics.

Associated Press writer Kirsten Grieshaber in Berlin contributed to this report.