France's Sarkozy warns Europe risks disintegration
He was addressing a gathering of European leaders of the centre right.
Mrs Merkel said it would take years to overcome the crisis, but that "we need to have more Europe".
EU leaders are preparing for a key summit in Brussels, where they will be trying to clinch a deal on how to tackle the eurozone debt crisis.
Mr Sarkozy of France has said that Europe is in much danger.
"Never has Europe been so necessary. Never has it been in so much danger," he said.
"Never have so many countries wanted to join Europe. Never has the risk of a disintegration of Europe been so great. Europe is facing an extraordinarily dangerous situation."
He said the eurozone economies still had a few weeks to decide, but that time was working against them.
"The diagnosis is that we have a few weeks to decide because time is working against us. If we aren't in agreement on this, I fear that we won't be able to agree on anything. That's the analysis."
Mrs Merkel has said changes to the European constitution are necessary. She said all 27 member states in the European Union had a duty to Europe, and had to work together to overcome the crisis in the eurozone.
National egos and interests had to be put aside, she added.
Germany and France are pushing for new EU treaties, saying stricter fiscal rules should be enshrined there.
As the leaders were speaking, the European Central Bank cut its interest rates back to their historic low of 1%, as expected by financial markets; Kazinform cites BBC.
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