The White House says that North Korea had failed to show seriousness for constructive dialogue with South Korea.

White House spokesman Robert Gibbs said in a press briefing that when inter-Korean talks broke down earlier this week, it was clear again that North Korea had no real intention of entering into a constructive dialogue. He added that this will result in further isolation of North Korea.

Gibbs also said that before returning to the six-party talks, the North must demonstrate a seriousness by living up to their commitments.

The U.S. State Department also earlier blasted Pyongyang for walking out of the working-level military talks with Seoul, indicating that the North had lost an opportunity to display their sincerity.