Eric Trump said his father should declare a national emergency to build a wall at the U.S.-Mexico border.

“I want him to declare an emergency,” Trump told Fox News Tuesday night. The president has said he will consider using a national emergency declaration to override congressional discussions and obtain the money for a border wall by executive action.

Democrats proposed a bill, which was passed and signed, that temporarily reopened the government for three weeks while discussions continued over President Trump’s demand of funding for a physical barrier at the southern border. The president had scuttled a bipartisan spending deal that did not include more than $5 billion for the wall, one of his signature campaign promises, which led to a five-week partial government shutdown starting Dec. 22.

“Let’s see if they [Democrats] were actually being truthful that once government was reopened that they would come to the table and negotiate something that’s fair,” said Eric Trump. “And honestly, if they don’t, declare the emergency, build the wall with the United States military, because that’s what people in this country want.”

[Related: Trump: Lawmakers are 'wasting their time' if they can't agree to a border wall]

Trump said that if Democrats, including some who have entered the race for president, were able to pass a lot of the changes they are looking to implement, the U.S. would be the next Venezuela.

Venezuela is in an economic and political crisis, and the U.S. has recently recognized its opposition leader as the country's president.

“They’ve become so radicalized, and it’s not going to work. They’ve become crazy,” Trump said. “The message does not make sense anymore. It's almost anti-American. It’s totally open borders.”

He pointed to comments made in November by Sen. Kamala Harris, D-Calif., who compared U.S. Immigration and Customs Enforcement to the Ku Klux Klan .

Harris has declared she is running for the 2020 Democratic nomination for president.