US President Donald Trump has signed an executive order to temporarily suspend the approval of certain Green Cards for a period of 60 days.
The order does however contain exceptions - including for American citizens' spouses and unmarried children under the age of 21; Green Card applicants already living and working in the US; those seeking entry to work as doctors, nurses or other healthcare professionals; and temporary guest visas issued each year to applicants like farm labourers and skilled workers in the H-1B visa programme.
Trump said the order will protect American workers' jobs in an economy that has been hard hit by the COVID-19 pandemic.
"This will ensure that unemployed Americans of all backgrounds will be first in line for jobs as our economy reopens," the president said at Wednesday's coronavirus briefing at the White House.
The order is aimed at stopping “chain migration” or the practice of Green Card holders sponsoring their extended families for permanent US residency.
The order also suspends the Diversity Visa Lottery, which issues about 50,000 Green Cards annually.