WASHINGTON - Most Americans doubt the US government is prepared to respond to a nuclear emergency like the one in Japan, a new Associated Press-GfK poll shows. But it also shows few Americans believe such an emergency would occur.

Nevertheless, the disaster has turned more Americans against new nuclear power plants. The poll found that 60 percent of Americans oppose building more nuclear power plants. That's up from 48 percent who opposed it in an AP-Stanford University Poll in November 2009.

The Associated Press-GfK poll comes as Japan continues to struggle with a nuclear crisis caused by a March 11 earthquake and tsunami. The crippled Fukushima Dai-ichi nuclear plant has leaked radiation into the environment and radioactive water gushed into the Pacific Ocean. Japan was rattled by a strong aftershock and tsunami warning Thursday, but officials reported no immediate sign of new problems.

The poll finds that about a fourth of those surveyed were highly confident that the US government is prepared to handle a nuclear emergency, while almost three-fourths were only somewhat or not confident.

But many people doubt such an emergency will happen in the US.

About three in 10 think such an emergency is extremely or very likely, compared with seven in 10 who think it is only somewhat or not likely. Among people who think a disaster is highly likely, almost eight in 10 lack confidence the government would be ready.

Even among those think it's not too likely or not at all likely to happen, almost two-thirds still lacked confidence the government would be ready.

The poll indicates that nearly one in four Americans lives within 50 miles (80 kilometers) of a nuclear power reactor. Those who reported living within 50 miles (80 kilometers) of a nuclear plant were not significantly more or less likely to have confidence in the government's ability to handle a nuclear disaster.

Those who live close to nuclear power plants were less likely to be strong opponents of building more nuclear power plants than those who live farther away. A total of four in 10 of those who live more than 50 miles (80 kilometers) from a plant strongly oppose building new ones, compared with three in 10 who say they live within 50 miles (80 kilometers) of a plant.

US government regulators are reviewing safety at the nation's 104 nuclear reactors in the wake of the Japanese crisis. The Nuclear Regulatory Commission says it will look at the plants' ability to protect against natural disasters and terrorist attacks, respond to complete power blackouts and cope with accidents involving spent fuel, among other issues.

The NRC says US nuclear plants continue to operate safely.

The Associated Press-GfK Poll was conducted March 24-28 by GfK Roper Public Affairs and Corporate Communications. It involved landline and cellphone interviews with 1,001 adults nationwide and has a margin of sampling error of plus or minus 4.2 percentage points.