"We are at war with a virus that threatens to tear us apart," World Health Organization Director-General Tedros Adhanom Ghebreyesus told world leaders Thursday, in a special virtual summit on the COVID-19 pandemic.
The deadly coronavirus, Tedros said, "is the defining health crisis of our time."
As the WHO head spoke, the number of coronavirus cases worldwide was reaching the 500,000 mark. More than 20,000 people have died, and both Italy and the U.S. are poised to surpass China atop the list of countries with the most coronavirus cases.
In the U.S., thousands of National Guard members are bolstering vital support systems, such as helping to distribute supplies at food banks. An increasing share of the world's population is under orders to stay at home; many schools and businesses are being told to shut down.
Two weeks after deeming the viral respiratory disease a global pandemic, Tedros told those attending the G20 Extraordinary Leaders' Summit on COVID-19, "The pandemic is accelerating at an exponential rate."
He noted that while it took weeks for the first 100,000 cases to accrue, the most recent 100,000 cases were reported over the course of just two days.
Millions of people could die if governments don't take aggressive action against the coronavirus, Tedros said. The summit's participants included the world's most powerful leaders, from President Trump to China's President Xi Jinping.
The pandemic is doing damage to the world's social, political and economic systems that will only be revealed with time, Tedros said.
The head of the WHO concluded his speech by making three requests of his audience.
"First, fight. Fight hard. Fight like hell," Tedros said. "Fight like your lives depend on it – because they do."
Urging aggressive action to to stop the virus, the WHO head said:
"Many of your countries have imposed drastic social and economic restrictions, shutting schools and businesses, and asking people to stay at home.
"These measures will take some of the heat out of the epidemic, but they will not extinguish it.
"We must do more. We must immediately build, expand, train and deploy health workers to find, test, isolate and treat every case and trace every contact. This is not an option; it's an obligation."
His other requests were for the world's most influential countries, to unite in the fight against coronavirus to share strategies and resources, and to ignite their industries' innovation, to create vaccines and therapeutics and to form "a global movement to ensure this never happens again."
"We may speak different tongues and adhere to different creeds, but we are made of the same stuff. We are one human race," Tedros said.
"Fight. Unite. Ignite.
"And let our singular resolve be: never again."