Biden visits South Korea's national cemetery

STORY: Biden laid a wreath in front of the memorial tower, burnt incense and paid silent tribute to soldiers who died during the 1950-53 Korean War.

Biden and Yoon will meet in Seoul on Saturday for their first diplomatic engagement since the South Korean president's inauguration 11 days ago.

The friendly encounter between allies is clouded by intelligence showing North Korean leader Kim is prepared to launch nuclear or missile tests.