Europe’s Schengen zone may keep its borders shut until September, to defend itself against the threat of COVID-19 from U.S. and other travelers. French President Emmanuel Macron has raised the possibility of the usually border-free countries staying shut to most foreigners for six more months, Forbes reported.

During a videoconference last Friday with trade unions, Macron said the idea is being considered by Schengen members, according to French media reports. The reason he gave was the fact that the pandemic is evolving at a different pace around the world, and “did not affect all countries at the same time.”

So the implication is that Europe needs to protect itself from the threat posed by travelers coming from high-risk countries. “Emmanuel Macron notably cited the example of the United States, where the coronavirus crisis is delayed by several weeks and which will therefore reach its peak later,” BFMTV reported. “But also that of Africa, where the situation is developing differently. In Asia, a second peak may occur.”

Macron’s comments came two days after European Union officials called for member states to extend the border closure for another month at least, until mid-May.