"It is an agreement between the U.S. and the Republic of Korea for those dates, " Lapan said.

CNN: China key to restraining North Korea, U.S. officials say

Lapan said the exercise in international waters will be similar to others in the past, including one with the George Washington last year.

CNN: China key to restraining North Korea, U.S. officials say

David Lapan, a Pentagon spokesman, said.

CNN: Headlines aside, 'don't ask, don't tell' stays in place

Dave Lapan of the Pentagon.

CNN: China key to restraining North Korea, U.S. officials say