The move is seen as a means of addressing public concerns over potential security risks posed by vendors for big infrastructure projects.
Boris Johnson and Ursula von der Leyen have until Sunday to reach a deal after Brexit trade deal talks stalled.
More than 6,600 new COVID-19 infections were reported by authorities on Thursday morning, beating a previous record set on March 28.
East Germany joined the western federal republic on October 3, 1990, following the collapse of the Soviet regime less than a year before.
The opposition figure was in hospital in Berlin being treated for Novichok poisoning when Merkel came to the hospital for "a private meeting".
The German Chancellor, Angela Merkel, met with Italian premier Guiseppe Conte Monday, ahead of the EU summit on Friday, but said that the positions of the member states remain apart. But she urged her counterparts to consider the bigger picture.