The United States resumed its annual military exercise with South Korea after a temporary halt to coordinate with Seoul over shelling across the border with North Korea, a senior U.S. official said on Friday.
"That exercise was suspended temporarily, I believe the day before yesterday, in order to allow the U.S. side to coordinate with the South Korean side on the ... exchange of artillery," David Shear, assistant secretary of defense for East Asia, said at a news briefing.
"That exercise has resumed as planned," Shear said. The military exercise, code-named Ulchi Freedom Guardian, began on Monday and is due to end next Friday.
North Korea regularly condemns the exercises as a preparation for war and on Thursday, according to Seoul, fired four artillery rounds into South Korea in apparent protest against cross-border propaganda broadcasts.
The South fired back 29 artillery rounds over the demilitarized zone (DMZ) dividing the countries.
A Pentagon spokesman, Commander Bill Urban, said the exercise was halted for "a brief period immediately following (North Korea's) firing of a projectile into (South Korea)."
Earlier, a U.S. official said the United States and South Korea had taken a "pre-scheduled pause" in the exercise.
Pyongyang accused the South of inventing a pretext to fire into the North and put its troops on a war footing on Friday, prompting China to voice concern and urge both sides to step back.
Shear said the United States was "very concerned" by what he said was a violation of the 1953 Korea armistice agreement by North Korea.
"We call upon North Korea to cease provocations across the DMZ and restore calm to the peninsula," he said.
North and South Korea are technically still at war as the 1950-1953 Korean War ended in an armistice, not a peace treaty.
The two sides have often exchanged threats, and dozens of soldiers have been killed in clashes, but they have always pulled back from a return to all-out war.
The United States has kept a military presence in South Korea since the war and it now numbers 28,500 personnel.
(Reporting by David Brunnstrom; additional reportng by Arshad Mohammed; Editing by Susan Heavey, David Storey and Mary Milliken) / Photo credit: <a href="http://www.defense.gov/About-DoD/Biographies/Article/602767">U.S. Department of Defense</a>