The shuttering of the U.S. economy due to the coronavirus pandemic is a shock of historic proportions that will likely push the national unemployment rate to 16% or higher this month and require more stimulus to ensure a strong rebound, a White House economic adviser said on Sunday.

"It's a really grave situation," President Donald Trump's adviser, Kevin Hassett, told the ABC program "This Week."

"This is the biggest negative shock that our economy, I think, has ever seen. We're going to be looking at an unemployment rate that approaches rates that we saw during the Great Depression" of the 1930s, Hassett added.