Akhir 1432 / 14 March 2011, SPA -- US government officials on Monday said they were confident in the safety of US nuclear power plants and rejected calls from some lawmakers to impose a moratorium on the building of new plants, according to dpa. There was also a "very low probability" that the possible meltdown of a nuclear reactor in Japan would impact Hawaii or the US coastline, according to Gregory Jaczko, who heads the US Nuclear Regulatory Commission (NRC). The threat of a nuclear meltdown in Japan, brought on by Friday's massive earthquake, has prompted many countries to review their use of nuclear energy. Some US politicians called on President Barack Obama to temporarily halt the planned construction of nuclear power plants, which generate about 20 per cent of electricity in the United States. There are no plants currently under construction, although the NRC is considering licensing for some to be built. White House spokesman Jay Carney dismissed calls for a moratorium and said nuclear energy "remains a part of the president's overall energy plans." But Carney and Jaczko stressed that US authorities would consider any safety lessons learned from Japan's disaster. "All our plants are designed to withstand significant natural phenomenon," Jaczko told reporters in Washington. But he added: "We will look at whatever information we can gain from this event and see if there are changes we need to make to our system." But Jaczko declined to say whether US nuclear plants were designed to withstand the 9.0 magnitude quake that struck Japan.