WASHINGTON—President Trump on Tuesday said a significant investment in infrastructure should be part of a fourth congressional coronavirus relief package, citing an opportunity in low interest rates.

“With interest rates for the United States being at ZERO, this is the time to do our decades long awaited Infrastructure Bill,” Mr. Trump wrote on Twitter. “It should be VERY BIG & BOLD, Two Trillion Dollars, and be focused solely on jobs and rebuilding the once great infrastructure of our Country!”

Asked...