German Chancellor Angela Merkel has called for the eventual creation of a European army, echoing a similar suggestion by French President Emmanuel Macron.

"We should work on the vision of creating a real European army one day," Merkel said in an address to the European Parliament in the French city of Strasbourg.

"A common European army would show the world that there will never again be war between European countries," she added, noting that it would not be at odds with the NATO defence alliance.

Last week, Macron had renewed his call for a European army that would give Europe greater independence from the United States, in comments that provoked criticism from US President Donald Trump.

The issue is controversial, however, with member states reluctant to give up national sovereignty on defence issues.

The EU already has so-called battlegroups to respond in crisis situations, however these have never been deployed.