WASHINGTON — North Korea’s claim of having built a new uranium enrichment facility could have serious implications for U.S. national security but may be nothing more than a “publicity stunt,” Obama administration officials said Monday.

Officials also tried to calm fears raised by the disclosure that Pyongyang had built a small but advanced industrial-scale facility, presumably giving North Korea a new facility for producing fuel for nuclear weapons, saying it has not created a crisis.

White House press secretary Robert Gibbs called on the North to return to the six-party talks between Pyongyang and the U.S., South Korea, China, Russia and Japan.

“We do not wish to talk simply for the sake of talking,” Gibbs said. “The North Koreans have to be serious about living up to their obligations.”

At the State Department, spokesman P.J. Crowley told reporters that the administration is studying the evidence a group of visiting American scientists used to conclude the North was building the enrichment facility.

“We are doing due diligence” before deciding how to respond, Crowley said. He added that consultations with Japan, South Korea and China were ongoing in light of the disclosure that he compared variously to a “publicity stunt” and a “show and tell” exercise.

This “show-and-tell from North Korea has potentially serious implications,” he said. “I’m not dismissing the potential significance of this. But based on a relatively brief exposure to some technology by itself we can’t, you know, draw implications about how mature this capability may be.”