Chancellor Angela Merkel and other high-ranking politicians are marking German Unity Day on Thursday with a celebration in the northern port city of Kiel, Deutsche Welle reports.
This year's central festivities are taking part under the motto: "Courage connects."
German President Frank-Walter Steinmeier cautioned that the "great fortune that is German reunification" is an ongoing process and cannot simply be "placed in the nation's trophy cabinet."
"Rather, it remains unfinished. It challenges us, it demands something from us," Steinmeier wrote in a Facebook post at the start of the festivities.
Merkel echoed those sentiments in her weekly podcast ahead of the festivities, saying: "Much has been achieved in recent decades, but there's still much to be done."
Defense Minister Annegret Kramp-Karrenbauer praised the role the German military played in reunification while meeting with troops on board the frigate "Schleswig Holstein."
"Almost 30 years ago, members of two armies were united. Overnight, opponents became comrades," Kramp-Karrenbauer said. "That this was successful was mainly due to the fact that the people were determined and courageous enough to shape the future together."
Kramp-Karrenbauer added that the German military "as a visible symbol of the successful reunification of our country."