World leaders pledged billions of euros for research to find a vaccine against the new coronavirus, but warned that it is just the start of an effort that must be sustained over time to beat the disease, AP reported.

At a video conference summit, United Nations Secretary General Antonio Guterres said that the 7.5 billion euros target being sought to help find a vaccine, new treatments and better tests for the disease would be merely a down payment on the tools that will be needed to fight the virus.

"To reach everyone, everywhere, we likely need five times that amount," Guterres said.

Two hours into the EU-hosted summit, just over 5.4 billion euros had been pledged, according to a European Commission tally.