ANYONE travelling to the United States will need to provide proof of a negative coronavirus test in order to enter the country.
The rule will come into effect on January 26.
American authorities have put the strict system in place in an attempt to reduce the transmission of Covid-19, particularly with the UK and South African variants spreading rapidly.
82 Americans have already been infected with forms of the new variants, dubbed 'super-covid', which are thought to be around 70% more transmissible than the original strain of the virus.
On Christmas Eve, the US imposed the rule for only those travelling from the UK, but since the outbreak of the variant has spread, they've expanded the requirement to all travellers.
Passengers will be required to get tested no more than three days before their flight to the States, and must show evidence of a negative test before boarding.
The rule will apply even to American citizens returning home in the coming days, according to The Wall Street Journal.
The Centers for Disease Control and Prevention (CDC) have also stated that anyone arriving in the US with a negative test will be required to get tested again between three and five days after arrival.
They must also stay in one location for seven days post-travel.
"Testing does not eliminate all risk," said CDC Director Dr Robert Redfield in a statement.
"But when combined with a period of staying at home and everyday precautions like wearing masks and social distancing, it can make travel safer, healthier, and more responsible by reducing spread on planes, in airports, and at destinations."
It comes on the same day Ireland announced the same rule, restricting arrivals only to those who can provide proof of a negative coronavirus test in the last 72 days, though exemptions have been made for children under the age of six, international transport workers, and gardaí going about their duties.
Ireland's rule doesn't require passengers to get tested for a second time after they arrive, however.