Travelers from outside Europe will soon be unable to enter the EU, under a new plan aimed at slowing the spread of the new coronavirus and preventing any added burden to national health systems.

Officials in Brussels hope that closing the bloc's external borders would convince EU countries to avoid imposing restrictions within the EU. But so far, there is no sign that governments such as Hungary and the Czech Republic that have imposed border controls with other EU countries are intending to reverse the measures.

The goal of the proposed external border shutdown is to limit the spread of the outbreak in both directions, said one EU diplomat, adding that it is also aimed at “reducing pressure on our health system which can’t welcome in this moment foreign nationals for non-urgent care.”

Here's POLITICO's guide to the EU border shutdown:

What is being proposed?

The European Commission has proposed a temporary restriction of non-essential travel from third countries into the EU+ area (the Commission does not like the phrase "travel ban"). That area includes nearly all EU members plus Iceland, Liechtenstein, Norway and Switzerland. The move could include Ireland — which has an opt-out from the Schengen Agreement — and the United Kingdom if they decide to align.

Who proposed it?

European Commission President Ursula von der Leyen put forward the initiative on Monday. European heads of state and government endorsed it at a European Council video conference on Tuesday evening.

Why now?

“In the current circumstances, with the coronavirus now widespread throughout the EU, the external border regime offers the opportunity of concerted action among Member States to limit the global spread of the virus,” reads the Commission's proposal to governments, in a plea for EU countries to act in unison.

“A temporary travel restriction could only be effective if decided and implemented by Schengen States for all external borders at the same time and in a uniform manner,” it said.

Does the EU have the power to do this?

Brussels is proposing the idea, but it does not have the power to implement it. The Commission is asking each government to introduce its own restrictions on entering their country from outside the EU+ area. Brussels wants EU countries to coordinate as much as possible for harmonized implementation.

But the Commission can do very little on enforcement: When asked what would happen if they decided not to follow suit, Commission spokesperson Adalbert Jahnz said that the border restrictions would be a coordinated set of "national decisions" and therefore enforceable only by member countries under national law.

Whom will it apply to?

EU citizens and citizens of Iceland, Liechtenstein, Norway and Switzerland will be permitted to enter the EU+ area to return home.

Non-EU+ citizens would temporarily not be allowed into the bloc, but there are exemptions. According to von der Leyen’s proposal, the restrictions would not apply to people transporting goods and other transport staff.

Long-term residents under the Long-term Residence Directive or who hold long-term visas, are family members of EU nationals, as well as people traveling for “imperative” family reasons will be allowed to enter. Health care professionals, health researchers and elderly-care professionals would also be exempt.

Frontier workers commuting legally into an EU nation from neighboring countries would be allowed in. There are also exemptions for diplomats, military personnel and humanitarian workers. Moreover, the restriction would also not apply to passengers in transit and asylum seekers.

How will it work?

Much remains uncertain about how the new measures would be implemented, since every member country would have to put its own rules in place.

How long will it last?

Von der Leyen said the restrictions "should be in place for an initial period of 30 days, which can be prolonged as necessary." The Commission’s communication notes that possible prolongations depend "on further developments.”

Will it apply to UK citizens?

They are still to be treated in the same way as EU citizens until the end of 2020. They can therefore continue traveling to the Continent.

How about goods?

Much like the Commission, countries are keen to stress that nothing should upend a steady flow of goods and plan to steer clear of restrictions on freight transport. “There shall be no restrictions on the movement of goods, regardless the country of origin,” said Jovita Neliupšienė, Lithuania's ambassador to the EU, adding that her country “fully supports” the EU’s approach.

Some governments are currently highly concerned about the impact of internal border controls on the flow of people and goods, with Neliupšienė pointing to the hundreds of Latvians, Estonians and Lithuanians "stuck in trucks, cars and buses" on the Polish-German border.

What about internal EU borders?

For the Commission — which on Monday also put forward new guidelines for border management within the bloc — part of the motivation for closing the external borders to third country nationals is to try to roll back many governments’ decisions to place controls on their borders with other EU members.

“It is more efficient and less disruptive than the closure of borders within Europe, which must be avoided to allow border workers to continue working and for essential goods to move in Europe,” the first diplomat said.

In its communication to governments on external border restrictions, the Commission wrote that the new plan would “enable the lifting of internal border control measures, which several Member States have recently reintroduced in an effort to limit the spread of the virus. These measures risk having a serious impact on the functioning of the Single Market as the EU and the Schengen area is characterised by a high degree of integration, with millions of people crossing internal borders every day.”

But some officials are skeptical that closing the external border would persuade crisis-focused governments to relax their new controls with EU neighbors.

The Czech Republic intends to keep its current measures — preventing most non-Czech citizens from entering the country — in place even after Tuesday's meetings of EU leaders, said one senior official.

“It’s going to be a problem to open up the internal borders, for many member states,” said a second diplomat.

Maïa de La Baume contributed reporting