U.S. President Donald Trump signed an executive order on Wednesday blocking the issuance of green cards for 60 days.

The order does not apply to people entering the United States on a temporary basis, and also includes exemptions for those who are currently in the country and those seeking entry to work as physicians and nurses, as well as the spouses and minor children of American citizens.

Trump's decision aims to protect unemployed American workers from competing with newly-arrived immigrants in the job market, as the U.S. struggles to restart its economy amid the spread of COVID-19. Trump also said he would consider extending the immigration suspension and adding more restrictions depending on the economic conditions.

More than 22 million Americans have lost their jobs and filed unemployment claims during the pandemic.

"This will ensure that unemployed Americans of all backgrounds will be first in line for jobs as our economy reopens," Trump said on Wednesday.

Jessica Vaughan, director of Policy Studies at the Center for Immigration Studies, a research institute based in Washington, D.C., said the immigration restrictions would "instantaneously create" job opportunities for Americans.

But others criticized the move, saying Trump appeared "more interested in fanning anti-immigrant flames than in saving lives" and that he hoped to win the November presidential election by playing to the immigration issue as he did in 2016.

There have been sweeping immigration changes over the past month, even before the executive order signed on Wednesday. The U.S. State Department has temporarily stopped processing routine visas at U.S. embassies and consulates due to the virus. U.S. borders with Mexico and Canada have also been closed to eliminate non-essential travel. Asylum and refugee admissions have also been blocked.

(Cover photo: President Donald Trump speaks about the coronavirus in the James Brady Press Briefing Room of the White House, April 22, 2020, in Washington. /AP)