Published: Mar 11, 2013 11:33 PM EDT

WASHINGTON (AP) - President Barack Obama's spokesman says the White House is concerned by war threats coming from North Korea.
    
North Korean state media said Monday that Pyongyang was cancelling the 60-year-old armistice that ended the Korean War.
    
White House press secretary Jay Carney responded that Pyongyang will achieve nothing with threats. But he said the White House is "concerned by North Korea's bellicose rhetoric."
    
Obama National Security adviser Tom Donilon told a meeting of the Asia Society in New York the claims may be "hyperbolic." He said the United States will protect its allies if Pyongyang uses any weapons of mass destruction or transfers nuclear materials.
    
Meanwhile, the Treasury Department is placing sanctions on North Korea's primary foreign exchange bank and a senior government official, a move aimed at slowing Pyongyang's ballistic missile and weapons of mass destruction programs. David Cohen, U.S. Treasury undersecretary for terrorism, says the bank facilitates transactions to North Korea's weapons proliferation network.