The Greek Parliament approved a controversial new property tax Tuesday, its latest effort to satisfy international creditors that it is committed to cutting its debt to secure a new round of financing next month to avoid a government default.

The new tax was announced earlier this month and has deeply angered Greeks already beset by a year of salary and pension cuts and increased taxes. Greece plans to collect the property tax on consumers' electric bills, threatening them with a power cutoff if they do not pay it.

The tax was approved on a day that Greek leaders voiced new confidence that the country will be able to carry out its austerity plan. Greek Prime Minister George Papandreou told German business leaders that his government is making a “superhuman effort” to cut its debt. He lashed out at critics of his country, saying that if they only heap “punishment and scorn” on Greece, the nation's financial crisis will not be resolved.

Mr. Papandreou said he can “guarantee” that Greece will live up to all its commitments made to its creditors, and predicted the country will eventually emerge from its deep recession to return to growth and prosperity.

The prime minister spoke ahead of a night-time meeting with German Chancellor Angela Merkel on the debt crisis. Speaking at the same business forum as the Greek leader, Mrs. Merkel said she has “absolute respect” for the spending reforms the Papandreou government has adopted.

But she offered no new German financial assistance for beleaguered Greece, saying that Berlin is “not available” for more more stimulus programs. The German government said the European bailout fund does not need to be increased beyond its current size – $594 billion.

Some financial analysts say the fund needs to be increased by several trillion dollars, in case other European countries besides Greece eventually need large-scale financial assistance.

Greece is looking to secure a new $11 billion portion of its bailout from last year in order to keep its government operating and avoid a default on its financial obligations – in effect, by borrowing more to repay loans. International creditors are expected to return to the Greek capital in the next day or two to continue their examination of the government's financial records, to determine whether Athens is adhering to its commitments before deciding whether to release the money.

The European debt crisis, particularly worries over a possible Greek default, has roiled international stock markets in recent weeks. U.S. President Barack Obama said Monday that the financial crisis is “scaring the world,” claiming that European leaders have not acted quickly enough to deal with it.

His comment drew a sharp rebuke Tuesday from German Finance Minister Wolfgang Schaeuble. He said Europe's debt crisis is not the reason for the sluggish U.S. economy and high unemployment.

Schaeuble said it is “always much easier” to give advice to others and said he is “well prepared” to do the same for the U.S.