"It has become clear that the goal of this Administration is to end immigration all together," the union head said.
USCIS said that any FY2020 cap-subject H-1B petitions filed before April 1, will be rejected.
In his February national address, the president said, "Legal immigrants enrich our Nation and strengthen our society in countless ways."
The Department of Justice sued to strip Norma Borgono, who played a minor role in a $24 million fraud scheme, of her American citizenship in May.
There will be at least 27 naturalization ceremonies on the Fourth of July.
USCIS has already identified 2,536 naturalization cases requiring an in-depth review, with 95 being referred to the Justice Department for civil denaturalization.
Sunlight's Web Integrity Project says as many as 26 documents for Training of Asylum Officers were pulled from USCIS's main pages and "cannot be found anywhere else on the site."
"As of May 21, 2018, the USCIS has received over 5,000 tips to the dedicated H-1B email address," USCIS spokesperson Philip Smith said.
USCIS will send those affected a prepaid envelope to return their incorrect cards within 20 days of receiving a notice.
The lawsuit claims that USCIS with its new policy memo overstepped its role in overseeing the H-1B visa program.
U.S. Citizenship and Immigration Services said the temporary suspension will allow it to process petitions that have been pending for a long time.
Restrictions have led many H-1B visa holders in the U.S. to move or contemplate moving north to Canada.
The new mission statement no longer says the U.S. is a nation of immigrants.
The proposal is part of Trump's "Buy American, Hire American" initiative he promised on the campaign trail.
Tens of thousands of Haitians live in the U.S. under Temporary Protected Status.
The USCIS was set to launch this year's round of H-1B visa program for skilled foreign workers—and it has not changed significantly despite President Donald Trump's vowed major reforms.