Conservative commentator Ann Coulter mocked President Trump as he unveiled his immigration plan Thursday.

"If you become VERY proficient at English," she tweeted at the president, "someday you will understand the meaning of the word 'WALL.'"

If you become VERY proficient at English, @realDonaldTrump, someday you will understand the meaning of the word "WALL." — Ann Coulter (@AnnCoulter) May 16, 2019

The new immigration plan would require immigrants to know English and pass a civics exam before being admitted to the U.S., Trump said from the White House.

[Related: Coulter celebrates Kirstjen Nielsen's resignation: 'Hallelujah!']

“To promote integration, assimilation and national unity, future immigrants will be required to learn English and to pass a civics exam prior to admission,” he said.

Coulter was a staunch supporter of Trump during the 2016 election but has soured on him with his lack of success building his proposed wall along the U.S.-Mexico border, especially when Republicans held control of the House and Senate during his first two years in the White House.

When Trump declared a national emergency at the southern border in February, Coulter said the “only national emergency is that our president is an idiot.”

[Also read: Coulter takes victory lap after Trump backs down from border closure]