Merkel's two-day visit came four months after Greece emerged from its third and final bailout package.
After more than 150 years, Germany's last black coal mine will close in the Ruhr region, posing a gigantic geological and environmental challenge to the former industrial heartland.
Germany and France will reportedly seek to revive the long-delayed EU financial transaction tax by proposing that member states be allowed to use the revenues to reduce their EU budget contributions.
French President Emmanuel Macron has urged a Franco-German push to make Europe a stronger and more confident global player that could prevent "chaos" on the world stage.
Germany's Chancellor Angela Merkel warns that Europe must be prepared for a no-deal Brexit, as EU leaders seek to unblock stalled divorce talks with Britain.