South Korean President Lee Myung-Bak made a surprise visit Thursday to an island near the tense border with North Korea that was shelled by Pyongyang two years ago

South Korean President Lee Myung-Bak made a surprise visit Thursday to an island near the tense border with North Korea that was shelled by Pyongyang two years ago.
  
Stressing the need to defend the maritime border "to the last man," Lee said the 2010 attack on Yeonpyeong island was an example of North Korea's tendency to launch isolated, provocative assaults out of the blue.
  
His visit and comments are likely to fuel cross-border tensions, already raised by a series of niggling maritime confrontations, defections and a new US-South Korean deal to nearly triple the range of the South's missile systems.
  
"The reason that we build up (the military) is not only to bolster our means to retaliate but to prevent the North's provocation," Lee was quoted as saying by Yonhap news agency.
  
"If North Korea provokes us, we have to retaliate strongly. We always have to remain vigilant," he said, as he inspected an anti-artillery radar unit and artillery company on the island. "If the North makes any (conciliatory) gesture, it is just a ruse and at such times we have to keep up our guard all the more," he added.