The European Union was supposed to make a decisive show of unity at its first summit since sweeping reforms streamlined its decision-making procession.
The meeting had a simple agenda: agree on a climate change fund for developing nations and a batch of small-scale procedural reforms and foreign policy statements.
It broke up around midnight Thursday without agreement on the climate fund, denting the perception that shutting the leaders in a room without their usual army of advisers would speed up decisions.
Activists called it a flop, despite the summit reaching accord Friday morning.
EU leaders pledged $3.6 billion pledge and agreed to go to the Copenhagen climate summit next week offering to cut greenhouse gas emissions by 30 percent from 1990 levels by 2020 if other major polluters agree to more significant cuts.
EU leaders also called Friday for a possible tax on financial transactions, welcomed new U.S. troops for Afghanistan and said the EU would support new sanctions against Iran over its nuclear program.
Still, the two-day summit highlighted divisions between the bloc's rich and poor nations and underscored just how hard it is to get 27 leaders to agree even after the enactment of the Lisbon Treaty. The treaty features new rules to accelerate decision-making so that the EU can respond more swiftly to global issues such as defense, energy security, climate change and migration.
The problems with this week's meeting don't bode well for the climax next week of the Copenhagen summit, where about four times as many world leaders will attempt to broker a new global climate pact to replace the Kyoto Protocol.
Polish Prime Minister Donald Tusk said he was willing to join the bloc's efforts to slash carbon emissions, but only after his country has weaned itself off its reliance on coal-fired power stations and switched to nuclear energy _ likely after 2020.
Tackling global warming, "cannot mean a catastrophe for the Polish economy," Tusk told reporters.
Critics questioned whether the $3.6 billion fund was enough to help developing nations tackle global warming and whether much of the money was really new.
Swedish Prime Minister Fredrik Reinfeldt conceded that the EU pledge included aid earlier promised, but didn't say how much.
"Many EU members have a track record of repackaging or re-announcing existing aid commitments," said Anne-Catherine Claude of Action Aid. "This appears to be the case here too. Real leadership on climate change requires real money and the EU is clearly failing here."
European superpowers Britain, France and Germany each contributed about 20 percent of the $3.6 billion and Britain is pushing to raise the figure higher at the Copenhagen talks. Many poorer nations are believed to have made only token contributions to ensure the EU could present a united front. Summit organizers did not break out individual contributions.
AP writers Raf Casert, Aoife White, Tobias Schmidt and Barbara Schaeder in Brussels contributed to this report.