All but two of the European Union's 27 members have signed up to a new treaty on tighter fiscal rules.
Britain's refusal to sign was flagged well in advance.
"The key point for me here is what is in our national interest and our national interest is that these countries get on and sort out the mess that is the euro."
On the other hand,the Czech Republic's opposition to the deal that threatens sanctions for breaches of EU budget deficit limits is more puzzling for French President Nicolas Sarkozy.
"We have taken note of that decision, which is some kind of clarification, although I'm not sufficiently familiar with the ins and outs of what's going on in Prague to be able to understand why what was acceptable in December is no longer acceptable now."
The treaty, which demands the incorporation of tighter budget rules into each nation's legislation, is being welcomed by European Central Bank President Mario Draghi.
"It is the first step towards a fiscal union. It certainly will strengthen confidence in the euro area."
The summit in Brussels also agreed to bring in a 500-billion-euro European Stability Mechanism to back heavily-indebted countries a year earlier than planned.
But differences over austerity limits and Greece's unfinished debt restructuring talks wrecked hopes for a more upbeat message that Europe's getting to grips with its debt crisis.
Paul Chapman, Reuters.
