Migrants who burden the US healthcare system will not be allowed to enter the United States unless they obtain appropriate insurance within 30 days, President Donald Trump said in a proclamation.

"The entry into the United States as immigrants of aliens who will financially burden the United States healthcare system is hereby suspended and limited," Trump said in a statement issued by the White House on Friday.

"An alien will financially burden the United States healthcare system unless the alien will be covered by approved health insurance… within 30 days of the alien’s entry into the United States, or unless the alien possesses the financial resources to pay for reasonably foreseeable medical costs."

Trump said that the US healthcare system is being hit hard by uncompensated care and the government is making the problem worse by admitting thousands of immigrants who have not demonstrated any ability to pay for their healthcare costs.

Trump added that data has shown that lawful immigrants are three times more likely than US citizens to lack health insurance. Immigrants should not further saddle the American taxpayers with higher costs, he said.