German Chancellor Angela Merkel and French President Emmanuel Macron are pushing for a more united defense industry, citing renewed ties between the two nations as a way to bolster the safety of the European Union in the face of flagging American support.

At a signing of a Franco-German treaty in the western German city of Aachen, an extension of the landmark 56-year-old Elysee Treaty at the heart of bilateral relations, Merkel lauded closer ties between the two nations on defense and foreign policy.

"We're committing ourselves to a common military culture, a common defense industry, a common line on weapons exports," Merkel said at the signing ceremony Tuesday. "With this, we both want to do our part to contribute toward a European army."