SEOUL, South Korea — Secretary of State John Kerry warned North Korea's leader, Kim Jong-un, on Friday not to proceed with a test launch of its Musudan missile and underscored that his nation would be defeated if a conflict broke out.

The missile has a range of up to 2,500 miles, according to American officials, which means it has the potential to strike targets in South Korea, all of Japan and even Guam. South Korean officials said earlier this week that North Korea has made preparations to test the missile and an American official told reporters on Friday that a launch could come at any time.
There has been speculation that Mr. Kim might order the launch to commemorate the anniversary on Monday of the birth of Kim Il-sung, his grandfather and the founder of North Korea state or that it might be fired while Mr. Kerry is in the region.