The man who slashed the top U.S. envoy here earlier this year was additionally charged Wednesday with siding with North Korea in violation of the National Security Law.
  

Kim Ki-jong was originally accused of attempted murder, violence against a foreign envoy and business obstruction.
  

Prosecutors, however, brought the additional charge during a hearing at the Seoul Central District Court. 
  

The law prohibits South Koreans from supporting or praising North Korea.
  

Prosecutors said Kim attacked the envoy following the North's argument that South Korea-U.S. joint military exercises are a war rehearsal against the North, adding the books and other materials confiscated from Kim's home support North Korea's strategy of communizing South Korea.
  

Kim attacked Mark Lippert with a knife at a breakfast function in Seoul on March 5, leaving the U.S. ambassador with deep gashes on his face and arm that needed more than 80 stitches.     
  

Kim has claimed that the drills hamper efforts to reunify the two Koreas, which technically remain at war because the 1950-53 Korean War ended in a truce, not a peace treaty. (Yonhap)