"This is a dangerous provocation that casts a shadow over the implementation of the hard-won Feb. 13 agreement and its progress," the North Korean Foreign Ministry said in a statement, referring to an agreement last month where the North pledged initial steps toward dismantling its atomic weapons programs.
The North's denunciation of military drills in the South is not new, but the latest condemnation came just hours after North Korea's main nuclear envoy, Kim Kye Gwan, pulled out of the latest six-nation talks over its nuclear program in a dispute over North Korean funds frozen at a Macau bank.
The North's ministry said the "entire responsibility for all negative consequences from the exercises" lies with the U.S. and South Korea, in its statement carried by the official Korean Central News Agency.
The annual drills are set to run for a week starting Sunday, involving 29,000 U.S. troops and an undisclosed number of South Korean soldiers.
The U.S. and South Korea characterize the annual drills as purely defensive. But the North has condemned them as a rehearsal for an invasion.
Earlier Thursday, the nuclear-powered American aircraft carrier USS Ronald Reagan arrived at the South Korean port city of Busan for the exercises, reports AP.
About 29,500 U.S. troops are stationed in South Korea as a legacy of the 1950-53 Korean War that ended in a cease-fire, not a peace treaty leaving the two Koreas technically at war.