BRISBANE, Australia – President Barack Obama and other leaders of the world’s largest economies urged governments worldwide to swiftly send money, health-care workers and equipment to combat the deadly Ebola outbreak in the West Africa.

“We invite those governments that have yet to do so to join in providing financial contributions, appropriately qualified and trained medical teams and personnel, medical and protective equipment, and medicines and treatments,” the Group of 20 countries urged in a statement issued Saturday.

Some nations have contributed. But international health experts have warned that the response remains dangerously inadequate to meet the needs in Liberia, Guinea and Sierra Leone.

Obama for months has led the effort to urge others to contribute _ including this week on his eight-day trip to China, Myanmar and Australia _ but with limited success.

Australian Prime Minister Tony Abbott, in his opening remarks at the conference, said Ebola was one of the “many terrible problems” in the world that leaders faced. Australia has sent money and personnel to Africa.

“This is our message to the world, that government can deliver,” he said. “That’s what the world expects of us.”

But Australia caused controversy by becoming the first developed country to close  its borders to people traveling from West Africa. That decision led to a subtle rebuke by Obama Saturday at a speech at the University of Queensland.

“We cannot build a moat around our countries, and we shouldn’t try,” Obama said. “What we should be doing is making sure everybody has some basic public health systems that allow for early warning when outbreaks of infectious disease may occur. That’s not just out of charity. It is in our self-interest.”

The World Health Organization has received only a small fraction of the billion-dollar international request it made for donations to fight Ebola. Health organizations say the United States, China and the United Kingdom have contributed the most, and that many others remain noticeably absent.

Obama has asked Congress to approve a multibillion-dollar request to help fight Ebola, and authorized the deployment of 4,000 troops and sent hundreds of medical professionals to provide treatment and training. This week, the Pentagon reduced the number of troops committed to the Ebola campaign to 3,000, with defense officials explaining that local partners were providing more help than had been expected. About 2,200 U.S. troops are in Liberia, where on Monday the first of 17 U.S.-built treatment centers opened.

“We cannot do this alone. Others have come to the table … but the response from other parts of the world and other major powers has been very paltry,” said J. Stephen Morrison, senior vice president of the Global Health Policy Center at Center for Strategic and International Studies. “And this is despite a very aggressive diplomacy.”

Humanitarian agencies offer a variety of reasons for why countries have not contributed. Many countries in and near the Middle East _ Saudi Arabia and Turkey, for example _ already are giving heavily in response to the Syrian humanitarian crisis.

The issue was expected to come up again in a meeting with Obama, Abbott and Japanese Prime Minister Shinzo Abe on Sunday.

National security adviser Susan Rice said before the trip that Obama would spend his part of his week urging countries to play a more active role.

“At this stage there are many needs that remain unmet in the west African region, whether it’s financial resources, particularly for the U.N. appeal; health-care workers; beds; medical supplies _ all of those remain key requirements and the United States has played a very active and prominent leadership role not only through our own national contributions, but in galvanizing the rest of the international community,” she said. “But we continue to look to capable partners … to do their part.”

In the G-20 statement, the leaders urged the World Bank Group and International Monetary Fund to continue making money available to fight Ebola through loans, debt relief, and grants, and to explore new ways to address comparable crises in the future.

“G-20 members are committed to do what is necessary to ensure the international effort can extinguish the outbreak and address its medium-term economic and humanitarian costs,” the statement said. “We will share our experiences of successfully fighting Ebola with our partners, including to promote safe conditions and training for health-care and relief workers. We will work to expedite the effective and targeted disbursement of funds and other assistance, balancing between emergency and longer-term needs.”