Twenty-five European Union nations agreed to put the brakes on their own spending, during a summit in Brussels Monday.
The leaders signed a fiscal treaty designed to end the bloc's crippling debt crisis by capping deficits and government debt.
Except for Britain and the Czech Republic, all the EU countries signed the agreement.
"I think the fact that it was possible to come to an agreement not to only in the euro-area countries but by 25 members of the European Union was indeed very impressive," European Commission President Jose Manuel Barroso said.
The agreement includes strict debt brakes and makes it more difficult for deficit spenders to escape sanctions.
The deal is seen as an attempt to reassure financial markets that Europe is committed to taking control of the debt crisis.
However, some observers say it's only for show because EU rules already forbid excessive government spending -- rules that have been consistently ignored.