The European Commission on Tuesday told six EU nations to ease unilateral border restrictions they have set up to combat Covid-19, as it sought to coordinate a less restrictive approach to the movement of goods and people within the bloc.
The EU executive's Justice Commissioner, Didier Reynders, said it had given Belgium, Denmark, Finland, Germany, Hungary and Sweden 10 days to justify curbs he said had "gone too far".
"It is a necessity to go back to a coordinated approach to all the measures taken in relations with the free movement of people and goods in the European Union," Reynders said.
A European Commission spokesman said that, without a coordinated approach involving all 27 member states, "we risk fragmentation and disruptions to free movement and to supply chains - something we have witnessed again the past weeks."
Germany's Europe Minister Michael Roth defended his country's tightening of borders over outbreaks of more contagious coronavirus strains reported by its neighbours.
"These measures obviously put a massive strain on border regions, commuters and the transport of goods and the single market, but the protection of our citizens is paramount," he said ahead of talks with his EU peers.