Vaccination will not be required for children under age 18 to travel to the United States once officials lift a ban on international visitors, but they will have to show proof of a negative coronavirus test before boarding a flight, according to rules outlined Monday by the Biden administration.

With about two weeks to go before the United States lifts a travel ban on visitors from 33 countries, federal health officials offered more specifics for travelers and airlines before restrictions are lifted Nov. 8. Although vaccination won’t be required for children, most non-U.S. citizens and nonimmigrants arriving by air will have to show both proof of vaccination and proof of a negative coronavirus test taken within three days of departure.

“With science and public health as our guide, the United States has developed a new international air travel system that both enhances the safety of Americans here at home and enhances the safety of international air travel,” the White House said in a statement.

Federal health officials said the exception was made for children because many do not have access to or are not yet eligible for the vaccines. However, children must still be tested before traveling to the United States. Those traveling with vaccinated adults must be tested within the previous three days, while those traveling with unvaccinated adults or who are traveling alone must show proof of a negative test taken one day before their flight.

The new rules don’t require U.S. citizens and legal permanent residents to be vaccinated but do outline different testing requirements depending on their vaccine status. Those who have been vaccinated must show proof of a negative test taken within of their departure. Those who are unvaccinated must show proof of a test taken one day before their departure.

It will be up to airlines to verify a person’s vaccination and testing status, officials said. Many airlines already have systems that allow travelers to upload proof of a negative test and vaccine status. In addition, international visitors will have to provide information for how they can be reached in the United States for contact-tracing efforts.

“These are strict safety protocols that follow the science and public health to advance the safety of Americans here at home and the safety of international air travel,” a senior White House official said in a briefing with reporters.

The Biden administration announced in September that it was replacing the travel ban on international visitors with a system that would rely on vaccination, testing and contact tracing for visitors wishing to come to the United States.

The announcement was welcomed by the travel industry, which has been pushing the government for more than a year to lift the travel ban on travelers from 33 countries. With the ban in place, industry representatives feared the United States was losing ground to Europe, which began to ease travel restrictions for Americans this summer. Canada opened its borders on Aug. 9 to visitors from the United States who had been vaccinated.

Kevin M. Burke, president of Airports Council International-North America, said the new protocols will help the nation safely and securely reopen its borders.

“We appreciate the Biden administration’s commitment to working with industry on these complex challenges and we look forward to our ongoing work as the November 8 reopen date nears,” he said in a statement.

Since the announcement in September, the administration has slowly been laying the groundwork for lifting the ban. That included the Centers for Disease Control and Prevention deciding which vaccines would be accepted, specifying that travelers must have received those with full or emergency approval from the U.S. Food and Drug Administration or the World Health Organization.

In January, President Donald Trump announced a plan to end the travel ban, saying it was unnecessary because of his administration’s policy that required international travelers to provide proof of a negative test before boarding U.S.-bound flights. But within days of taking office, the Biden administration reinstated the ban and added South Africa, and later India, to the list, citing the need to control the spread of coronavirus variants.

In June, the White House formed working groups to help determine when to lift rules that banned international visitors from certain countries.

Under the restrictions, most foreign nationals who have been in the United Kingdom, several European Union countries, Brazil or China in the previous 14 days are not permitted to enter the United States. India was added to the list in May.

The White House also announced this month it was easing pandemic-related restrictions on overland border crossings from Canada and Mexico. Officials said Monday they would release additional information about requirements that people coming to the United States via land borders must follow.

The updated policy offers limited exceptions for individuals enrolled in certain coronavirus vaccine clinical trials and those who shouldn’t get vaccinated for medical reasons. Those who need to travel for emergency or humanitarian reasons and have a letter issued by the U.S. government verifying their need to travel also may be exempted.

In addition, those with non-tourist visas coming to the United States from countries where there is low vaccine availability as determined by the CDC may be allowed to travel to the United States. Those who receive exemptions but intend to stay for more than 60 days may be required to get vaccinated once in the United States.