SEOUL (Reuters) -- U.S. and South Korean troops began annual military drills on March 9 and North Korea said it had put its armed forces on full combat readiness in response to the exercises, heightening tensions on the Korean peninsula.
North Korea, which is preparing to test-fire its longest-range ballistic missile, also said it would regard the shooting down of any of its rockets as an act of war.
The North Korean army said in a statement that the drills were a "military provocation" that would only occur "on the eve of a war."
Pyongyang regularly accuses the United States and South Korea of aggressive intentions before the exercises, which have been held for years without major incident.
But North Korean media has been more strident about these drills, which come as Pyongyang is making preparations to test-fire its Taepodong-2 missile and at a time of speculation about the health of North Korean leader Kim Jong-il.
North Korea has repeatedly said it was preparing to launch a satellite as part of a peaceful space program.
"Shooting our satellite for peaceful purposes will precisely mean a war," a spokesman for the North's Korean People's Army said in a statement carried by the official KCNA news agency.
Last week the unpredictable state said it could not guarantee the safety of South Korean civilian aircraft flying near its airspace. That forced several airliners to alter their routes.
The military drills are scheduled to run until March 20, and are longer and on a greater scale than in previous years.
The aim is to test the defensive readiness of the combined U.S. and South Korean forces ahead of the transfer of war-time command from the U.S. to the South Korean military in the next several years.
Troops will be mobilised throughout South Korea, including Marines conducting live-fire drills north of the capital Seoul, which is less than two hours drive from the border with North Korea.
A U.S. aircraft carrier will take part in the exercises, the U.S. military said.
Envoy In Seoul
South Korean officials did not have any immediate comment on the latest rhetoric from Pyongyang, but the government of conservative President Lee Myung-bak has warned the North to cease provocative moves and return to dialogue.
South Korea, Japan, and the United States have said they saw no difference between a satellite and a missile launch because they use the same technology and the same rocket. The North is barred from launching a ballistic missile under UN sanctions.
The new U.S. special envoy for North Korea, Stephen Bosworth, will hold talks with South Korean officials in Seoul on March 9 that are likely to focus on trying to restart talks on ending the North's nuclear arms program.
Bosworth, on a tour of North Asian capitals, last week said the North's continued threats were undesirable.
Six-party talks aimed at coaxing Pyongyang to carry out nuclear disarmament have been under way for several years.
The two Koreas are technically still at war and station about 1 million troops near their respective sides of the Demilitarised Zone that has divided the peninsula since the 1950-53 Korean War ended in a ceasefire, but not a peace treaty.