""European participants are of the opinion that this is urgently necessary to prevent such crises from happening again in the future," Merkel said in her weekly podcast. Leaders of the 20 biggest developed and developing economies meet on June 26-27 in Toronto, Canada. Merkel's stance contrasted with that of U.S. President Barack Obama, who this week said public finance problems should be addressed "in the medium term" -- a warning that clamping down budgets should not be done at the expense of recovery. European governments have been launching austerity measures to head off a spread of the debt crisis begun...