Mark Ralston/AFP/Getty Images

Cruise line operators Carnival, Royal Caribbean and Norwegian have been hit hard by the coronavirus pandemic. But the three companies aren't getting any help from Washington, D.C., as of now.

Shares of all three stocks plunged between 12% and 20% Friday after the Senate and House passed a more than $2 trillion coronavirus aid package that did not include any money for them.

The reason? The cruise lines all have headquarters in Miami, but none of them is legally based in the United States — which allows them to pay fewer taxes. Carnival is incorporated in Panama, while Royal Caribbean is headquartered in Liberia. Norwegian is incorporated in Bermuda.

Republican US Sen. Josh Hawley of Missouri noted that fact in a tweet earlier this week, urging them to move to America in order to qualify for aid.

President Trump said in a news briefing Thursday that “it’s very hard to make a loan to a company when they’re based in a different country." But he also noted the cruise companies employ thousands in the United States and that "we’re going to try and work something out.”

Carnival CEO Arnold Donald said in an interview on the "Axios on HBO" show that the company is not looking for a government bailout. But Donald acknowledged that "capital markets are constrained right now." (HBO is a part of WarnerMedia, the AT&T-owned parent company of CNN.)