The US travel industry has welcomed the change as a "huge step forward."
The US has lifted COVID-19 testing requirements for international travellers arriving by plane.
Arrivals no longer have to show a negative COVID-19 test result or proof of recovery to enter the country, after the rule was scrapped at midnight on Sunday night (12 June).
A spokesperson for the Centre For Disease Control said the decision was made on the basis of high vaccine uptake and widespread population immunity.
"Each of these measures has contributed to lower risk of severe disease and death across the United States. As a result, this requirement which was needed at an earlier stage in the pandemic may be withdrawn," they said.
However, the organisation hinted that testing requirements could return at some point.
"CDC continues to evaluate the latest science and state of the pandemic and will reassess the need for a testing requirement if the situation changes," the spokesperson said.
Vaccine rules - banning non-vaccinated travellers from visiting the country - will remain in place. People under the age of 18, US citizens, US nationals, lawful permanent residents and green card holders are exempt from the vaccination requirements.
On Friday, White House assistant press secretary Kevin Munoz tweeted that the need for testing will be "based on the science and in context of circulating variants."
He added that President Joe Biden's work on vaccines and treatments was critical to the decision.
The travel industry has spent months lobbying the Biden administration to drop testing requirements that were in place since January 2021.
These entry rules required all travellers over the age of two - regardless of vaccination status or citizenship - to get a COVID-19 test no more than one day before travelling by air into the US.
Rapid antigen, PCR and a number of other kinds of tests were accepted.
Fully vaccinated visitors had to take another viral test within three to five days of arrival.
As of midnight on Sunday, both pre-departure and post-arrival testing requirements have been dropped - but the CDC still suggests that arrivals test before flying.
"CDC continues to recommend that those travellers boarding a flight to the U.S. get tested for current infection with a viral test as close to the time of departure as possible (no more than 3 days) and not travel if they are sick," a spokesperson said.
Such testing is not mandatory.
What did the travel industry think of the testing rules?
The travel industry has been lobbying for months to get the US government to drop COVID testing.
On Friday, US Travel Association president Roger Dow said the change in policy would "accelerate the recovery of the US travel industry".
"Today marks another huge step forward for the recovery of inbound air travel and the return of international travel to the United States," Mr Dow said.
Clive Wratten, chief executive of the Business Travel Association (BTA), said that the decision was a “clarion call” to countries that still have restrictions in place.
“All travel facilitators around the world need to help build customer confidence and deliver the travelling experience necessary for our sector’s recovery,” he said.
Airline Virgin Atlantic welcomed the decision, predicting a “boost” in consumer confidence.”
Last week, American Airlines CEO Robert Isom described testing requirements as "nonsensical" adding that they were "depressing" leisure and business travel.
Airlines for America chief Nick Calio added that requirement harmed the US economy. The trade association claimed that international trips are still 14 per cent lower than normal, while domestic travel has nearly recovered to pre-pandemic levels.
"Quite frankly, the only impact the pre-departure testing requirement is having is a chilling effect on an already fragile economy here in the US," Calio explained.
In May, more than 260 travel firms signed a letter to the White House demanding an “urgent repeal” of the pre-departure testing rule.
“It is time for the Biden administration to lead the country toward a new normal for travel and on a faster road to a full economic recovery,” according to the letter from the US Travel Association (USTA).
The decision to drop testing comes six weeks after a federal judge blocked President Biden’s plan to extend mandatory mask-wearing on planes, trains and other public transport on 18 April. This means masks are now optional as far as the US transit authority is concerned.