The U.S. administration cited "international security issues" as the reason for U.S. Secretary of state Mike Pompeo's visit to Berlin being canceled, a German government source told Reuters.

Pompeo had been due to meet German Chancellor Angela Merkel and Foreign Minister Heiko Maas in the German capital later on Tuesday.

Earlier, a U.S. Embassy spokesman cited scheduling reasons for the cancellation and quoted a State Department spokesperson as saying Pompeo looked forward to visiting Berlin soon.

Merkel's office confirmed the cancellation "by the American side" but referred other questions to the U.S. Embassy, which had no further comment.

Maas said he had talked with Pompeo by telephone, and they had agreed to find another time for a meeting soon.

Pompeo has been taking part in a meeting of the Arctic Council in Finland. It wasn't immediately clear where he would be heading next.