SEOUL, South Korea (AP) - South Korea's president vows North Korea will "pay a price" for a March torpedo attack that sank a warship and killed 46 sailors.
At least part of that price is trade.
In a solemn speech from the halls of the country's War Memorial, President Lee Myung-bak told the nation that Seoul has "always tolerated North Korea's brutality," because it has "a genuine longing for peace." But, he says, "now things are different."
Lee's first steps include cutting trade ties with Pyongyang and barring North Korean cargo ships from South Korean waters. Experts estimate the measures will cost the North about $200 million a year.
The White House is offering its full support for South Korea's moves.
The two Koreas are still technically in a state of war because the Korean conflict of the 1950s ended with a truce, not a peace treaty.