Democratic presidential candidate Hillary Clinton speaks during a town hall meeting in Las Vegas, Nevada August 18, 2015. [Photo/Agencies]

WASHINGTON - US Democratic presidential front-runner Hillary Clinton on Tuesday distanced herself from President Barack Obama's fresh approval for offshore drilling in the Arctic.

"The Arctic is a unique treasure," said Clinton on Twitter. "Given what we know, it's not worth the risk."

Clinton's breakaway from the Obama administration came only one day after Obama gave the oil company Shell the green light to drill for oil off Alaska's coast, and was so far Clinton's clearest disagreement with the Obama administration's agendas.

Earlier this year, Clinton refused to take a stand on either the proposed Keystone Xl oil pipeline or the Trans-Pacific Partnership, and her statement on Tuesday came at a time when she was struggling with the lukewarm support from the progressive wing within her own party.

After she staked out her opposition to Arctic drilling, Republican presidential candidates immediately issued their accusations, with former Florida Governor Jeb Bush bashing Clinton as "Being more-anti energy than Obama is extreme."

Bush said energy revolution should be embraced to lower prices and create jobs at home.

As the country is embracing itself for another presidential election in the coming year, Arctic drilling is believed to be a contentious issue as more Arctic sales are slated for 2016 and 2017.

Environmentalists have long opposed the Arctic drilling, fearing that any oil spill would cause irrevocable damages to the local eco-system.