German Chancellor Angela Merkel likened Russia’s effort to annex Crimea to the imperialism of past centuries and said that President Vladimir Putin risks “massive economic and political harm” to his country.

Addressing lower-house lawmakers in Berlin today, Merkel combined calls for Russia and Ukraine to hold talks with threats of strengthened European Union sanctions as early as next week if Putin doesn’t “contribute to detente” before the separatist referendum in Crimea scheduled March 16.

“We’re experiencing a conflict that concerns spheres of influence and territorial claims,” Merkel said in her speech to the lower house, or Bundestag. “A conflict that in fact we know from the 19th and 20th centuries and one we’d have thought we’ve overcome. But quite plainly it hasn’t.”

Merkel, who grew up under Moscow-enforced Communism in East Germany, is the focal point of Europe’s response to the crisis over Ukraine in part because of Germany’s economic ties with Russia. She joined President Barack Obama in pressing Russia to halt the referendum in Crimea that both have said is a violation of international law.

Russian-speaker Merkel and Putin, who speaks German, have talked by phone repeatedly during the crisis. If Russia doesn’t back down, “it won’t just be a catastrophe for Ukraine,” Merkel told lawmakers. “It would also cause massive economic and political harm to Russia.”

Escalating Sanctions

EU foreign ministers will impose sanctions including asset freezes and visa restrictions at a meeting on March 17 unless Russia agrees to start talks on a diplomatic solution, Merkel said. EU leaders at an emergency summit on March 6 threatened Russia with escalating sanctions over its actions in Ukraine.

“No one among us wants this to happen,” Merkel said. “But we would all be ready and determined to do this if it was unavoidable.”

Russia supplies 35 percent of Germany’s natural gas and has an economic interest in keeping up deliveries, which are often based on long-term contracts, Merkel was quoted as saying in an interview with today’s Passauer Neue Presse newspaper. At the same time, Germany’s energy mix is diversified enough to avoid dependence on Russia, she was quoted as saying.

While citing Russia’s role in global economic forums such as the Group of 20 and in diplomacy including nuclear talks with Iran, Merkel suggested in her speech that the Ukraine crisis won’t be over soon.

“I’m afraid we have to dig in for the long haul to solve this conflict,” she said. “Conflicts of interest in the middle of Europe in the 21st century can only be overcome by not resorting to the methods of the 19th and 20th centuries, but to the principles and means of our time, the 21st century.”