The United States and South Korea began a series of annual joint military exercises Saturday, after days of threats by North Korea that it will retaliate if the war games turn into an attack — threats generally made each year.
The annual U.S. and South Korean exercises last eight weeks and are meticulously planned. Saturday's activities began with U.S. and South Korean troops in assault vehicles storming a beach on South Korea's east coast.
South Korea's Defense Ministry is calling the exercises "the largest scale ever," with 300,000 South Korean and at least 17,000 U.S. troops participating.
A U.S. statement released before the exercises began said about 55 U.S. Marine aircraft and 30 U.S. and South Korean ships are taking part in the war games near Pohang City.
North Korea's military has said it is prepared to counter the U.S. and South Korean forces "with an ultra-precision blitzkrieg strike of the Korean style."
In response, South Korea's Defense Ministry has warned Pyongyang against "rash behavior" and "provocations."
Missing N. Korean sub
Meanwhile, CNN reports a North Korean submarine has gone missing off the east coast, prompting a search that U.S. officials say seems to have lasted several days. U.S. military officials say they have been watching the investigation for days.
It is unclear whether the sub is adrift underwater or has sunk entirely, but officials say it was carrying out an exercise when it seemed to suffer some type of failure.
In another development, North Korean state media report that leader Kim Jong Un ordered the country to improve its nuclear attack capability after watching a recent ballistic missile launch test.
North Korea's official Korean Central News Agency (KCNA) quoted Kim saying he wanted "more nuclear explosion tests to estimate the destructive power of the newly produced nuclear warheads and other tests to bolster up the nuclear attack capability."
It says Kim declared that the DPRK would make its enemies "regret their misjudgment" and "reckless action."
On Thursday, North Korea fired two short-range ballistic missiles that traveled about 500 kilometers before falling into the water off the country's east coast.
Response to drills
The missile tests were likely in response to massive military drills by South Korea and the United States, which Pyongyang has called a preparation for invasion.
Following the tests, Pyongyang said it will "liquidate" all remaining South Korean assets on its territory, referring to two abandoned joint projects: the Kaesong industrial complex and the Mount Kumgang tourism resort, both inside North Korean borders.
The North's Committee for the Peaceful Reunification of Korea also said it is nullifying all agreements with South Korea on economic cooperation and exchange programs, and threatened military and economic actions against the South Korean government.