U.S. Secretary of State John Kerry has released a video message congratulating South Koreans on the occasion of the anniversary of Korea\'s independence from Japan\'s 1910-45 colonial rule. It is unusual for the U.S. secretary of state to make a video appearance for a congratulatory message on a foreign anniversary because such messages are usually issued in writing. The video message was made in consideration of the 60th anniversary this year of the alliance between the two countries, a diplomatic source said.