Chancellor Angela Merkel says Germany is prepared to talk about treaty changes if they're needed to implement reforms in the European Union.Speaking at the side of French President Emmanuel Macron, Merkel said Monday that European countries must not think that the union should never make treaty changes.She says: "A European Union that behaves this way would be vulnerable from every corner of the world." But she also made clear that treaty changes were not a topic immediately on the table."First we need to work on what we want to change, and then if it turns out it needs a treaty change, then we're prepared to do that," she said.Macron reiterated that the EU needs a roadmap for change, and he would also be prepared to change treaties if necessary.Merkel called for a "new dynamism" in German-French relations, saying that the two countries' interests are closely tied together.She told Macron during his first foreign visit as president Monday that "Europe will only do well if there is a strong France, and I am committed to that."Merkel said it was an honor that Macron chose to visit Berlin during his first full day in office, and said the countries' ministers would meet after an upcoming French legislative vote. She said the two talked about the European asylum system, trade relations and other issues."We each represent the interests of our own countries, but the interests of Germany are naturally closely tied to the interests of France," Merkel said.Macron's foreign policy drive will focus on Europe. An advocate of closer European Union integration, Macron backs a "multi-speed" Europe, an idea that has seen growing support in Germany and other EU countries since Britain voted to leave the bloc.In the past, France has often been seen by its allies as an intransigent, go-it-alone power because of its military interventions in arenas like Libya, the Middle East and the Sahel. Macron wants deeper security cooperation with Europe, but he may find it hard to break the mould of predecessors Francois Hollande and Nicolas Sarkozy."We know that in the world in which we live in it's not the president who imposes foreign policy, but foreign policy that imposes itself on the president," said Francois Heisbourg, a Macron adviser and chairman of the International Institute for Strategic Studies.Later in the week Macron will visit thousands of French troops fighting militants in West Africa, three years after they first deployed to Mali. Before the end of the month, he will meet U.S. President Donald Trump and attend NATO and G7 summits in Brussels and Sicily. A significant shift in French diplomacy was unlikely, one French diplomat said. "I don't think there will be a major break from the past," the diplomat told Reuters. "All the main subjects will see continuity."