Elizabeth Warren said Wednesday she would oppose the building of new nuclear plants in America and work to phase out existing nuclear power from the energy mix.

"In my administration, we won't be building new nuclear plants," Warren said at CNN's climate change town hall. "We will start weaning ourselves off nuclear and replace it with renewables," she added, saying that she would aim to do so by 2035.

Warren had previously not taken a position on nuclear power in any of her various climate change plans, including a new proposal she issued earlier Wednesday requiring utilities to achieve 100% carbon-neutral power by 2030 and reaching all-renewable electricity generation by 2035.

While few Democratic candidates are explicitly cheering on nuclear power, most recognize that it provides more than half of the nation’s zero-carbon electricity.

However, Warren and other opponents such as Bernie Sanders cite concerns about storing nuclear waste, and the high cost of building new plants, in opposing it.

Sanders wants to impose a moratorium on license renewals for existing power plants, along with stopping the building of new plants.

It's unclear if Warren's opposition to nuclear power includes smaller advanced reactors that are being developed, but not yet commercialized, for greater safety and easier construction than today’s massive plants.