The United States says North Korea’s pledge to impose a moratorium on nuclear testing is insufficient to reopen the stalled six-way nuclear talks.

State Department spokeswoman Victoria Nuland told reporters on Wednesday that the fact that the communist state is willing to refrain from nuclear test and missile launches would be a welcome first step but would not be enough to restart the stalled multilateral dialogue.

She said that the North’s uranium enrichment facilities disclosed last November remain a matter of serious concern to the U.S. She said the North’s uranium enrichment activities violate obligations under U.N. Security Council Resolutions 1718 and 1874 and are contrary to the pledges Pyongyang made in 2005.

Asked if the U.S. has been in contact with Moscow about details of its summit talks with North Korea, Nuland said Washington expects to make contact after North Korean leader Kim Jong-il's visit to Russia ends.