German Foreign Minister Sigmar Gabriel on Wednesday, 8 March warned his Turkish counterpart Mevlut Cavusoglu that comparisons with Nazi Germany are "lines that must not be crossed".
"The Turkish side said it wanted to be treated equally with respect but I believe both sides have a responsibility and there are lines that must not be crossed and any comparison with Nazi Germany is one of them," he was quoted as saying by BBC.
The development comes after Turkish President Recep Tayyip Erdogan recently compared present day Germany to Nazi rule as the country withdrew permission for rallies that involve Turkish ministers in German cities such as Cologne, Frechen and Gaggenau.
Erdogan is seeking new constitutional powers through a referendum on 16 April. At least 1.4 million expat voters in Germany are eligible to vote in the referendum.
Erdogan described the move to withdraw rally permissions as anti-democratic and made Nazi comparisons. But, Germany said those decisions are made by city councils and are based on security concerns.
However, Gabriel has also expressed a wish to go back to having friendly relations with Turkey and shed a light on the success of the two countries' alliance.
Meanwhile, Russia's decision to permanently deploy Iskander missiles in its enclave in the Baltic Sea, Kaliningrad, is a cause of concern for European security, Gabriel told Russian news agency Interfax.
"If Iskander missiles were stationed in Kaliningrad permanently, that would be a cause for great concern and a blow to European security. That is why we are watching what's happening in Kaliningrad very carefully," he was quoted by Reuters as saying.
In October, Moscow said that it had moved the nuclear capable missiles to Kaliningrad and reportedly stationed an S-400 air missile defence system. Moscow said at the time that it was a part of routine drills but military officials in the West are concerned that it could become permanent.