Fifty-eight percent of Americans think U.S. nuclear power plants are safe, while the public remains split over the need for more plants following Japan's nuclear crisis, a Gallup poll showed Monday.

The March 25-27 survey of 1,027 U.S. adults found public confidence in nuclear safety relatively unchanged since 2009, when a Gallup poll said 56 percent of Americans believed U.S. plants were safe.

In the new poll, 58 percent said U.S. nuclear power plants are safe, 36 percent said not safe and 6 percent had no opinion.

The survey showed a slight uptick in concern that the dangers of nuclear power are too great to justify construction of more nuclear plants in the United States.

Forty-eight percent of respondents said the dangers are too great, compared with 46 percent who believe more U.S. nuclear plants are necessary.

A Gallup poll conducted in early 2001 found 49 percent in favor of nuclear expansion and 46 percent against it.

President Barack Obama on March 17 requested a comprehensive review of U.S. nuclear power facilities, maintaining his support for nuclear energy while seeking to apply lessons from the crisis at Japan's Fukushima plant stricken by an earthquake and tsunami.

Nuclear energy supplies about 20 percent of U.S. electricity.