BERLIN - Germany's foreign minister expressed cautious optimism on Wednesday that Berlin and Ankara may begin to slowly reel diplomatic relations back to normal, following an escalation of tensions that culminated with Turkish President Recep Tayyip Erdogan accusing Germany of "Nazi practices".

Foreign Minister Sigmar Gabriel said talks in Berlin with Turkish Foreign Minister Mevlut Cavusoglu, the first face-to-face official meeting since the diplomatic crisis began last week, were "good, honest and friendly, but also hard and contentious".

Over the past week, German municipalities have canceled several events in which Turkish Cabinet ministers had planned to address rallies in Germany in support of a national referendum on constitutional reform that would give Erdogan more powers. Officials have cited issues of overcrowding and fire safety, among other things.