WASHINGTON — The United States still wants to expand nuclear plant construction despite the Japan disaster and sees nuclear power as a key part of clean energy efforts, Energy Secretary Steven Chu said Wednesday.

Testifying at a House subcommittee hearing about President Barack Obama's request for energy funds in the fiscal year 2012 budget, Chu defended the US nuclear industry, which provides about 20 percent of America's power.

Nuclear energy "has an important role to play in our energy portfolio," Chu said, noting that the president's budget asks Congress for $36 billion in loan guarantee authority to "jumpstart the domestic nuclear industry."

Asked by Texas Democratic Congressman Joe Barton if Obama still supports nuclear construction in the United States, given the crisis in Japan following a potent quake and tsunami there last week, Chu answered:

"We are asking for loan guarantees. The present budget is also calling for small modular reactors. That position has not been changed."

Barton responded: "So that's a yes?"

"Yes," Chu answered.

"Given, again, what has happened, do you and the president want Congress to support the full 36 billion that you have put in the budget?" Barton asked.

"Yes," Chu said.

The US nuclear industry has largely stalled, with no new plants built to completion since the March 28, 1979 accident at Three Mile Island, a partial reactor meltdown that led to "very small" releases of radioactivity, according to the US Nuclear Regulatory Commission (NRC).

No one was killed or injured in the incident, but it stirred an outcry that blocked further expansion of the US nuclear program.

"I think the events unfolding in the Japan incidents actually appear to be more serious than Three Mile Island. To what extent we don't really know now," Chu added.

An attempt to launch nuclear renaissance in the United States has faltered due to heavy costs associated with reactor construction, which the Obama administration hopes can be overcome through government-backed loan guarantees.

Obama vowed on Tuesday to "further improve" the safety of US atomic facilities.