NEW : Another U.S. delegation to head to Asia , sources say . NEW : Japan sending an envoy to Korea to discuss the Korean crisis . Top U.S. , Japanese and S. Korean diplomats discuss recent N. Korean actions . U.S. Joint Chiefs chairman to head to South Korea to demonstrate solidarity .
NEW : Another U.S. delegation will go to Asia , sources say . NEW : Japan sending an envoy to China to discuss the Korean crisis . Top U.S. , Japanese and S. Korean diplomats condemn recent N. Korean actions . U.S. Joint Chiefs chairman to head to South Korea to demonstrate support .