The White House said North Korea has yet to prove that it is capable of deploying missiles armed with nuclear warheads.

White House Press Secretary Jay Carney said that while North Korea has conducted nuclear weapons tests, and has developed some missile technology, there are no official intelligence reports acknowledging that North Korea can fire a missile armed with a nuclear warhead.

But Carney said that the U.S. is taking North Korea’s plans to develop nuclear weapons seriously and is closely monitoring the situation. He said the U.S. is calling for North Korea to meet its international obligations.

Carney also said recent threats of war by North Korea were reminiscent to its past patterns of behavior and said there were other options open for the North Korean regime should it promise to denuclearize the Korean peninsula.