Officials say Turkey's president has expressed concerns over plans in Germany's parliament to recognize the World War I killings of Armenians as genocide.

Recep Tayyip Erdogan's office says the concerns were relayed Tuesday during a telephone conversation with German Chancellor Angela Merkel.

The killings of 1.5 million Armenians by Ottoman Turks are widely viewed by historians as the first genocide of the 20th century. Turkey strongly denies that the deaths constituted genocide, insists that the toll was inflated and says those killed were the victims of civil war and unrest.

Germany's parliament will hold a vote on a motion describing the deaths as genocide on Thursday.

Erdogan's office said the Turkish leader told Merkel it was "important that a prudent approach is displayed."