Germany on Monday inaugurated the centre to boost defence readiness in the Baltic Sea region as Russia pursues its Ukraine offensive.

The Russian ministry said it expressed a "decisive protest" to the ambassador over the creation of the centre in Rostock.

It said in a statement that "In Washington, Brussels and Berlin, they must realise that the expansion of NATO military infrastructure in former East Germany will have the most negative consequences".

Moscow warned that this "will not remain without a corresponding response from the Russian side".

The foreign ministry also said the new centre was a "blatant breach" of the treaty on the reunification of Germany in 1990 that said no foreign armed forces would be deployed in the area.

The centre in the port city of Rostock will be led by a German admiral and manned by staff from 11 other NATO countries.

It will aim to "coordinate naval activities in the region" and provide NATO with a "maritime situation picture in the Baltic Sea region around the clock", according to the German defence forces, according to Germany's Defence Minister Boris Pistorius.