The United States is calling North Korea’s threat to conduct a second nuclear test “an irresponsible move.”

White House National Security Council spokesman Mike Hammer reiterated Wednesday that what the U.S. wants is a denuclearized Korean Peninsula.

He added that until such an objective is realized, the U.S. will continue to provide security, including a nuclear umbrella, to South Korea and Japan.

The State Department said the North is further isolating itself from the international community with such threats, and stressed the need for the communist state to come back to the negotiating table. The department also urged China and Russia to play active roles in convincing the North to return to the nuclear talks.

Meanwhile, U.S. media have called on Washington to come up with measures to combat such threats from the North, which have escalated since U.S. President Barack Obama came into office 100 days ago.

The Washington Post said in an article titled “No More Bribes,” that North Korea is once again attempting to provoke an American president. The report said the North wants to hold bilateral talks with the U.S., excluding South Korea, in a bid to gain economic and political concessions.