Recent announcements of American military deployments in response to belligerent statements by North Korea may have contributed to escalating tensions between the two countries, Pentagon officials told CNN on Thursday in explaining an effort to reduce U.S. rhetoric about the reclusive state.
"We accused the North Koreans of amping things up, now we are worried we did the same thing," one Defense Department official said.
They spoke on the same day a U.S. official first told CNN that communications intercepts indicated North Korea may be planning to launch a mobile ballistic missile in the coming days or weeks.
Classified images and communications intercepts show that North Korea has moved up to two mobile missiles, launchers and fuel tanks to its East coast, another American official with knowledge of the matter told CNN.
South Korean Defense Minister Kim Kwan-jin told a parliamentary committee in Seoul that the activity signaled an imminent test firing or military drill, according to the semi-official South Korean news agency Yonhap.
One U.S. official said it is believed any launch this time would be a test.
The activity is consistent with a Musudan missile, the official said.
The Musudan is based on a Soviet-era system and has a 2,500-mile (4,000-kilometer) range that can threaten South Korea, Japan and Southeast Asia, but not U.S. forces based on Guam.
As a vital ally to South Korea since the Korean war in the 1950s, the United States has pledged military backing to Seoul in the event of an attack by North Korea.
In addition, North Korea has been developing nuclear weapons technology, raising concerns of rapid proliferation in the region and even a possible nuclear strike by Pyongyang.
The fraught situation on the Korean Peninsula stems from the North's latest long-range rocket launch in December and underground nuclear test in February.
In response, the United States helped bring tougher U.N. sanctions on North Korea and took part in joint military exercises with South Korea, prompting Kim Jong Un's government to ratchet up its threats in recent weeks.
That caused the United States to display its military strength in the annual drills taking place now, flying B-2 stealth bombers capable of carrying conventional or nuclear weapons, as well as Cold War-era B-52s and F-22 Raptor stealth fighters over South Korea.
On Thursday, a North Korean army official warned that "the moment of explosion is approaching fast."
"No one can say a war will break out in Korea or not and whether it will break out today or tomorrow," said the spokesman for the General Staff of the North's Korean People's Army (KPA).
"The responsibility for this grave situation entirely rests with the U.S. administration and military warmongers keen to encroach upon the DPRK's sovereignty and bring down its dignified social system with brigandish logic," the KPA spokesman added in a statement published by the state-run Korean Central News Agency (KCNA).
A spokeswoman for the White House National Security Council said Thursday that the United States continues to closely monitor the situation.
"Threats and provocative actions will not bring North Korea the security, international respect, and economic development it seeks," said the NSC spokeswoman, Caitlin Hayden. "We will continue to urge the North Korean leadership to heed President Obama's call to choose the path of peace and come into compliance with its international obligations."
Earlier, a Defense Department official told CNN that from a communications point of view, "we are trying to turn the volume down" on U.S. rhetoric about North Korea. The official, speaking on condition of not being identified, said the change referred to public statements by the Obama administration instead of how U.S. military hardware were being deployed in the region.
According to the official, some Pentagon officials were surprised at how U.S. news releases and statements on North Korea were generating world headlines and therefore provoking a Pyongyang response.
"We are absolutely trying to ratchet back the rhetoric," the official said. "We become part of the cycle. We allowed that to happen."
At the State Department, spokeswoman Victoria Nuland said Thursday the United States needed to take the defensive steps it did in view of North Korea's threats, but she focused on a diplomatic solution available if Pyongyang changed its behavior.
"It was the ratcheting up of tensions on the DPRK side that caused us to need to shore up our own defense posture. We have done that," Nuland said. "But we have also been saying all the way through that this does not need to get hotter, that we can change course here if the DPRK will begin to come back into compliance with its international obligations, will begin to cool things down, take a pause."
To Bill Richardson, the former U.S. ambassador to the United Nations, the administration's response so far has been "appropriate -- cool, calm, but at the same time putting our military resources ready in case there's an emergency."
He told CNN on Thursday that a North Korean military attack on U.S. interests would be "suicidal," adding: "That's not going to happen."