U.S. Federal Reserve chief Ben Bernanke says a failure to resolve the debt crisis in Greece could threaten the global financial system.

At a news conference Wednesday, the head of the U.S. central bank said if Greece defaulted on its debt, the impact would go beyond Europe and pose threats to the global economy. He stressed that the Federal Reserve is not part of the negotiations to resolve the crisis, but has been “kept well-informed.”

Earlier Wednesday, Greek Prime Minister George Papandreou survived a crucial parliamentary confidence vote, making passage of the controversial economic reforms more likely.

Crowds in the square outside parliament reacted angrily to the vote. Riot police used tear gas to disperse protesters who broke off from the main rally.

Many Greeks said that while they understand the need to get the public debt under control, they feel the government, the European Union and International Monetary Fund are not going about it the right way.

But EU leaders are adamant that Greece move ahead with sharp economic reforms including increased taxes and privatizations of the public sector before they release the next $17 billion of last year's promised $160-billion bailout funds.

Wednesday's confidence vote fell strictly along party lines, indicating that Mr. Papandreou will continue to face challenges to the reform program. The vote passed with 155 lawmakers backing the government and 143 voting against it. Two abstained.

Mr. Papandreou is appealing to lawmakers to pass his package of spending cuts, tax increases, and the sale of state assets. He warned parliament that Greece would face bankruptcy and default next month if it fails to back his reforms and secure the loan payment.

The opposition and some members of the prime minister's own Socialist Party say the reforms will not work.

The United Nations warned Wednesday that austerity measures being adopted by many countries to avert bankruptcy are undermining the global economic recovery.

A U.N. report issued in Geneva says some of those tough reforms threaten public sector employment, public health and education programs, and spur social unrest.

The report also criticizes international institutions such as the IMF for attaching tough conditions to their financial assistance packages without paying sufficient attention to the social implications of such policies.