The nominee for the next U.S. secretary of defense vowed Wednesday to use the "full range of capabilities" to defend against North Korean ballistic missiles, saying they could pose a "direct threat" to the country.
  

Ashton Carter made the pledge in a written answer submitted to the Senate Armed Services Committee for his confirmation hearing, saying he would deploy more ground-based missile interceptors in California and Alaska, regions that could fall within the North's missile ranges.
 

Carter also said the North's intercontinental ballistic missile threat is "very real."
  

"North Korea's ballistic missile and weapons of mass destruction capabilities clearly present a serious and direct threat to U.S. forces postured in the Asia-Pacific region as well as to our regional allies and partners," Carter said.
  

"These capabilities, although untested at longer ranges, could also pose a direct threat to the United States ... If confirmed, I will ensure that we draw upon the full range of our capabilities to protect against, and to respond to, these threats," he said.
  

North Korea's history of proliferation activities amplify the dangers of its asymmetric programs, he said.
  

In addition to deploying more missile interceptors, Carter also said he would enhance the Pentagon's ability to highlight and disrupt the illicit proliferation networks that North Korea uses and promote cooperation with partners to interdict shipments of proliferation concern.
  

"With respect to ballistic missiles that could threaten the United States, I think that's one of the reasons why we need to keep our missile defenses and especially our ICBM defenses current, capable and large enough in size to deal with both the prospective Iranian threat and the also very real North Korean ICBM threat," he said during the hearing.
  

North Korea's missile program has long been a key security concern in the region and beyond.
  

The communist nation is believed to have developed advanced ballistic missile technologies through a series of test launches. In its latest rocket launch, conducted in late 2012, the North succeeded in putting a satellite into orbit aboard a long-range rocket.
  

The test sparked fears that the North has moved closer to ultimately developing nuclear-tipped missiles that could potentially reach the mainland United States. The country has so far conducted three underground nuclear tests in 2006, 2009 and 2013.
 

Carter said the North remains "one of the most intractable security problems" for the United States. He pointed out the communist nation continues to take destabilizing actions, including nuclear and missile tests as well as the cyberattack against Sony Pictures.
  

He added the limited information on the North, leader Kim Jong-un and the regime's motivations "add to my concern."
  

"Despite the recent signals from both North and South Korea about openness to inter-Korean engagement, the U.S. should remain vigilant against the strong possibility that North Korea will use brinkmanship and provocations to try to coerce the United States and its allies and partners back into negotiations on its own terms," he said.
  

Carter also vowed to further strengthen the alliance with South Korea, saying the alliance is "the critical linchpin to deterring North Korean aggression and maintaining stability on the Korean Peninsula."
  

He rejected the North's recent offer to suspend nuclear tests if the U.S. and South Korea halt joint military exercises, saying the annual drills are "routine, transparent, and defensive exercises that are meant to strengthen military readiness and alliance preparedness."
  

"There is no equivalence between conducting these exercises and North Korean nuclear tests, which are violations of United Nations Security Council resolutions," he said.
  

Carter said the North's hack on Sony is "serious and deserving of a response" but that he does not believe it rises to the level of an "act of war." (Yonhap)