Germany will aid Greece in defense of Europe's shared currency if Athens enforces austerity measures, Foreign Minister Guido Westerwelle said on Sunday, in a speech also calling for tighter EU budget rules.

Speaking to a convention of the Free Democrat party he leads as the junior coalition partner to Chancellor Angela Merkel's conservatives, Westerwelle said Germany would not let the euro zone be endangered by a single member state's problems.

We are ready to fulfill our duty to the currency and do it justice, he said, adding that Greece must take firm action to reign in its deficit. Prosperity and social justice require a stable currency, but we aren't giving out any blank checks.

Debt-stricken Greece appealed to its European partners and the IMF for emergency loans on Friday, yielding to overwhelming market pressure to set in motion the first financial rescue of a member of the euro zone.

Germany stands to be the largest state aid contributor to Greece if the loan package is approved, and Berlin wants to ensure that Greece's savings effort are absolutely credible.

Greece must get its own house in order, for a start, and aid can only be given as last resort to protect our own currency, Westerwelle said.

In a newspaper interview published on Sunday, Finance Minister Wolfgang Schaeuble said that Greece must agree to tough new austerity measures before it receives any financial aid, and failure to do so would endanger such support.

The Greek crisis showed the euro zone needs stronger rules and oversight mechanisms to ensure member states obey the Stability and Growth Pact debt limits, Westerwelle said.

We need a stronger right of intervention for the European statistics agency Eurostat, we need an oversight system for budget deficits, we want to strengthen the stability pact.

(Reporting by Brian Rohan; Editing by Louise Heavens)