The United Nations has launched a US$2bn (€1.85bn) global humanitarian response to fight COVID-19.
This will focus on vulnerable countries across South America, Africa, the Middle East and Asia.
The UN humanitarian chief has warned that failing to help these vulnerable countries fight the coronavirus now could place millions at risk, and leave the virus free to circle back around the globe.
Governments are being urged to commit to fully supporting the global humanitarian response plan, while sustaining funding to existing humanitarian appeals.
COVID-19 has killed more than 16,000 people worldwide and there are nearly 400,000 reported cases.
It has a foothold across the globe and is now reaching countries that were already facing humanitarian crisis because of conflict, natural disasters and climate change.
The response plan will be implemented by UN agencies, with international NGOs playing a direct role in the response.
It will deliver essential laboratory equipment to test for the virus, medical supplies to treat people, install handwashing stations in camps and settlements and launch public information campaigns on how to protect yourself and others from the virus.
It will also set up airbridges and hubs across Africa, Asia and Latin America to move humanitarian workers and supplies to where they are needed most.
"Basic human solidarity"
UN Secretary-General António Guterres said: "COVID-19 is menacing the whole of humanity - and so the whole of humanity must fight back. Individual country responses are not going to be enough.
"We must come to the aid of the ultra-vulnerable - millions upon millions of people who are least able to protect themselves.
"This is a matter of basic human solidarity. It is also crucial for combating the virus.
"This is the moment to step up for the vulnerable."
WHO Director-General Dr Tedros Adhanom Ghebreyesus said: "The virus is now spreading in countries with weak health systems, including some which are already facing humanitarian crises.
"These countries need our support - out of solidarity but also to protect us all and help suppress this pandemic.
"At the same time, we must not fight the pandemic at the expense of the other humanitarian health emergencies."
While UNICEF's Executive Director Henrietta Fore added: "Children are the hidden victims of the COVID-19 pandemic.
"Lockdowns and school closures are affecting their education, mental health and access to basic health services.
"The risks of exploitation and abuse are higher than ever, for boys and girls alike.
"For children on the move or living through conflicts, the consequences will be unlike any we have ever seen. We must not let them down."
They have called on UN member states to commit to stemming the impact of COVID-19 in vulnerable countries and containing the virus globally by giving the strongest possible support to the plan.
They also warned that any diversion of funding from existing humanitarian operations would create "an environment in which cholera, measles and meningitis can thrive, in which even more children become malnourished, and in which extremists can take control".
An additional US$60m (€55.5m) has also been released from the UN’s Central Emergency Response Fund (CERF).