The South Korean and US military Monday began an annual major joint exercise to test defenses against North Korea, a drill denounced by Pyongyang which vowed to strengthen its nuclear deterrent

The South Korean and US military Monday began an annual major joint exercise to test defenses against North Korea, a drill denounced by Pyongyang which vowed to strengthen its nuclear deterrent, AFP said.
  
More than 30,000 US troops, including most of those based in the South plus 3,000 from overseas, are taking part in the drill known as Ulchi Freedom Guardian which ends on August 31, the US forces said in a statement.
  
Seoul's defence ministry could not say how many South Korean troops were taking part but Yonhap news agency put the number at 56,000.  

US and South Korean forces claim it is defensive while the North Monday called it a drill for a preemptive nuclear attack.
  
Pyongyang "will bolster up its war deterrent for self-defense to cope with the reckless moves of the US and the south Korean puppet regime for a nuclear war", said ruling party newspaper Rodong Sinmun, using a phrase referring to its nuclear weaponry.
  
General James Thurman, commander of the 28,500 US troops based in the South, called Ulchi Freedom Guardian "a key exercise in strengthening the readiness of Republic of Korea (South Korean) and US forces".
  
On the eve of the exercise, the North's leader Kim Jong-Un visited a frontline artillery unit which carried out the deadly 2010 bombardment of a South Korean island near the disputed western sea border.
  
Kim praised its personnel as heroes and told them never to tolerate enemy aggression, the North's official news agency reported Saturday.