With public confidence declining in President Bush's handling of the war in Iraq, nearly 70 percent of Americans feel the United States will be bogged down in the country for years without achieving its goals, a poll finds.

The Newsweek poll released Saturday also found that nearly 6 of 10 people are concerned that the U.S. military will be overextended should another security threat arise outside Iraq (search). And 7 of 10 are concerned the costs of the war will increase the deficit and hurt the economy.

The war costs the United States roughly $1 billion per week.

The poll of 1,011 adults was taken Thursday and Friday, just after last week's suicide truck bombing at the United Nations headquarters in Baghdad (search) that killed the top U.N. envoy there and at least 22 others.

U.S. and British troops have also been targets of guerrilla attacks. Military figures show that 135 U.S. soldiers have died in Iraq since May 1, when President Bush declared the end of major combat operations there.

Americans had mixed feelings over how to proceed. About 48 percent said the United States should withdraw military personnel because of the attacks, while 47 percent said the soldiers should stay.

About 61 percent said the United States did the right thing in taking military action, down 7 percent from a poll taken in late July.

And 72 percent say they would support turning over some authority for rebuilding Iraq to the United Nations. France, Russia, India (search) and other countries have ruled out sending soldiers to Iraq unless a multinational force is authorized by the United Nations.

The poll found that 54 percent approved of Bush's handling of the Iraqi situation, down from 58 percent in late July.

And for the first time in a Newsweek poll, the percentage of registered voters who would not like to see Bush re-elected as president outnumbered those who supported a second term (49 percent to 44 percent).

The poll had a margin of error of plus or minus 3 percentage points.