WASHINGTON — A federal appeals court on Friday declined to step into a dispute over the Obama administration’s cancellation of a planned nuclear waste dump in the Nevada desert, saying the matter must be left for now to federal regulators.

The United States Court of Appeals for the District of Columbia dismissed a suit filed by South Carolina and Washington State challenging the Department of Energy’s authority to withdraw a 2008 application to open the waste repository. But the court hinted that it might be ready to intervene if the Nuclear Regulatory Commission did not reach a decision on whether the department could withdraw the license request.

Congress directed the department in 1987 to develop an application to create the dump at Yucca Mountain, 100 miles northwest of Las Vegas, and instructed the Nuclear Regulatory Commission to determine whether the application met licensing requirements, which include isolating the radioactive waste for one million years.

But in March 2010, the Department of Energy withdrew its license request, making good on a campaign promise by President Obama.