France will require on-the-spot COVID-19 tests for people arriving from 16 countries where the pandemic is circulating widely, Prime Minister Jean Castex said Friday.

France does not allow general travel to and from these countries, which include the United States and Brazil.

The tests will be for "French citizens who live in these countries or citizens of these countries with an established residence in France," Castex told reporters at Paris's Charles de Gaulle airport.

Travellers testing positive will be required to spend 14 days in isolation to prevent the spread of the virus.

Castex said some of the high-risk countries already require airline passengers to show a negative virus test before boarding. It was not clear if those would be re-tested upon arrival in France.

He also did not specify if people would have to wait for their test results before being allowed to leave the airport.

Along with the United States and Brazil, which are reporting tens of thousands of new cases each day, the countries include Algeria, Bahrain, Israel, India, South Africa, Kuwait, Qatar, the United Arab Emirates, Oman, Panama, Peru, Serbia, Turkey and Madagascar.

Morocco, which has reported rising cases in recent weeks, is not on the list for now but could be added later, an official in the prime minister's office said.

Coronavirus tests will be rolled out across France by August 1, and will also be carried out at French ports, Castex said.

He also said that while France's border with Spain would remain open for now despite a surge in coronavirus cases in Catalonia, "we strongly urge French people to avoid going there until the health situation improves."

As for people travelling to France from Spain, "we are in talks with the Spanish and Catalan authorities so that... they try to limit the flow as much as possible," he said.