European Commission announced of Friday the introduction of a new category to classify the most severely affected coronavirus-hit areas. These zones, marked in dark red on maps periodically released to track the pandemic, will be put under even more strict restrictions, requiring travelers from those areas to undergo both test before departure and mandatory quarantine upon arrival at their destination.

“A dark red zone would show that in this zone, the virus is circulating at a very high level,” leader of the European Commission, Ursula von der Leyen, told reporters on Friday after an online summit of EU leaders which discussed ways to harmonize anti-pandemic measures across the bloc’s 27 countries.

Currently, the classification of areas depends on national health authorities of each country, which sometimes leads to contradictions.

As an example of this, Von der Leyen said that in some cases the border would be closed in one country’s border area while in the neighboring EU country with the same epidemiological situation it would remain open. Everyone from the first EU country would then go shopping to the other EU country and in the process increase the risk of spreading the virus, she said.

European Council President Charles Michel said that EU leaders agreed that it is necessary to consider the possibility of restricting all non-essential travel in the bloc.

“In terms of non-essential movements, restrictions should be possible to consider,” he said, adding that EU’s internal passport-free Schengen area borders still had to stay open to keep the bloc’s single market functioning.

Michel and Von der Leyen both pointed to the dangers of virus mutations and new, much more infectious, strains. EU leaders agreed that genome sequencing of the virus should be stepped up in order to detect new mutations as soon as possible.

Another topic were vaccination certificates, with Michel saying that there was agreement on using standardized certificates for medical purposes, but that it was too early to talk about using these for other purposes.

Greek Prime Minister, Kyriakos Mitsotakis, proposed that the certificates should serve as passports allowing EU nationals to travel across borders, in order to help jump start tourism activity.

But Michel said that it is still too early for that before a ‘sufficiently large number’ of people receive vaccinations, as otherwise it might lead to discrimination against people who did not get the opportunity to get vaccinated.