German Chancellor Angela Merkel arrives to sign a book of condolence for former Israeli President Shimon Peres at the embassy of Israel in Berlin, Germany, September 30, 2016. REUTERS/Michael Kappeler/POOL

BERLIN (Reuters) - Britain’s decision to leave the European Union is a warning to the rest of the bloc, which must learn to take decisions faster rather than looking to agree new treaties, German Chancellor Angela Merkel said on Friday.

“This is a warning shot to all of us to reconsider once again: What does Europe mean for us? What must Europe change to be successful in the eyes of the people?” Merkel said in a speech to her Christian Democrats in North Rhine-Westphalia.

She added that Europe must decide on what it needs to concentrate and where it can play less of a role, as well as learn to make decisions more quickly.

“We must not always talk about new treaties but about actions,” she said.

French presidential candidate Nicolas Sarkozy has said he could reverse Brexit if elected next year by negotiating a new EU treaty more acceptable to Britain. France and Germany have distanced themselves from the suggestion.