Germany's foreign minister has urged Turkey not to overreact to a decision by the German parliament to brand the 915 massacre of Armenians by Ottoman forces a "genocide".
Turkey, which rejects the notion that the killing of Christian Armenians during World War I amounted to a genocide, has recalled its ambassador to Germany in protest .
Turkeys Deputy Prime Minister said the vote was a "historic mistake".
Speaking on a visit to Argentina, the foreign minister said "as expected, Turkey has reacted, and I hope that we will succeed in the next days and weeks to avoid any overreaction."
The nature and scale of the killings remain highly contentious.
Turkey accepts that many Armenians died in partisan fighting beginning in 1915, but denies that up to 1.5 million were killed and that this constituted an act of genocide, a term used by many western historians and foreign parliaments.
Even before Germany's Bundestag lower house of parliament passed the symbolic resolution by an overwhelming majority, Turkey's prime minister had condemned the motion as "irrational" and said it would test the friendship between the NATO partners.
Within two hours, Turkey had recalled its ambassador to Germany for consultations and summoned a top German diplomat to the foreign ministry in Ankara, according to officials.
Armed riot police were deployed outside the German consulate in Istanbul, near Taksim square, in case of protests.
President Tayyip Erdogan, who is in Kenya, said the resolution would seriously affect relations with Germany and the government would discuss what steps they would take.
"The way to close the dark pages in your own history is not by besmirching the history of other countries with irresponsible and groundless parliamentary decisions," tweeted Foreign Minister Mevlut Cavusoglu.
A spokesman for the ruling AK Party responded swiftly to the vote, saying it had "seriously damaged" relations.
The timing could not be worse for Chancellor Angela Merkel, who is relying on the success of an EU-Turkey deal she has championed to stem the flow of migrants to Europe in return for cash, visa-free travel rights and accelerated talks on EU membership.
In an indication of how sensitive the issue was, she did not take part in the vote due to "public engagements".
Later, however, she put the emphasis on the close ties between the two countries.
"Even if we have a difference of opinion on an individual matter, the breadth of our links, our friendship, our strategic ties, is great," she told reporters when asked about it.
Over 1,000 demonstrated against the resolution on Saturday in front of the Reichstag building in Berlin.
Armenia welcomed the resolution. The foreign ministry said Turkish authorities continued "to obstinately reject the undeniable fact of genocide".
Nearly a dozen other EU countries have passed similar resolutions.