Bill Gates laid out a 3-step process the U.S. government must take to help curb the COVID-19 outbreak that could kill between 100,000 and 240,000 Americans, based on government estimates shared Tuesday.

The Microsoft co-founder and global health expert published his proposed plan in a Washington Post column Tuesday afternoon. Gates has been increasingly outspoken in recent days about the need to take more aggressive action in the fight against the novel coronavirus.

"There's no question the United States missed the opportunity to get ahead of the novel coronavirus," he wrote. "But the window for making important decisions hasn't closed."

Here's a recap of his plan:

Shutdown: Allowing states to enact their own social distancing mandates is a "recipe for disaster" because people can travel across state lines and spread the virus, Gates wrote. "Until the case numbers start to go down across America — which could take 10 weeks or more — no one can continue business as usual or relax the shutdown," he said. "Any confusion about this point will only extend the economic pain, raise the odds that the virus will return, and cause more deaths."

Testing: Gates said more tests need to be made available and the resulting data should be aggregated "so we can quickly identify potential volunteers for clinical trials and know with confidence when it's time to return to normal." He said there should also be clear priorities for who gets tested, given the lack of test-kits. He also called out the self-swab developed by the Gates-backed Seattle Coronavirus Assessment Network as an example of an efficient testing method.

Vaccine: Gates said a vaccine can be created in less than 18 months with a data-based approach and rapid trials. The federal government should help build facilities where the vaccines will be made, he said.

In the column, Gates also cited his 2015 Ted Talk in which he warned the world of a COVID-19-like pandemic.