WASHINGTON, United States -- COVID vaccine requirements taking effect next month for people entering the United States by air will not apply to children, a senior US official said Monday.

"For children under 18 there is a uniform exemption from that vaccination requirement," the senior official, who spoke on condition of anonymity, told reporters two weeks ahead of the reopening of US borders to much of the world.

The Biden administration announced earlier this month that land and air borders will reopen on November 8 to foreign visitors who have been fully vaccinated. This ends a more than 18-month suspension of travel from much of the globe, including close allies and trade partners like Canada and western Europe.

The vaccination requirement does not apply to US citizens and immigrants.

The official said the under-18 exemption reflected the fact that in many countries coronavirus vaccines have not been authorized or made available for minors.

Also exempted will be travelers from countries with a lower than 10 percent vaccination rate, due to lack of availability, which is the case across much of Africa and other large parts of the world.

However, all travelers, regardless of citizenship or vaccination status, will have to show proof of a negative coronavirus test.

For vaccinated passengers, the test can be taken within three days of travel, but for those not vaccinated the test must be within one day.

Only vaccines approved by the US regulator, the Food and Drug Administration, and the UN's World Health Organization will qualify. Although this includes the Chinese Sinopharm and Sinovac vaccines, those who used Russia's Sputnik V will remain shut out.