SEOUL, South Korea (AP) — A North Korean missile exploded during launch Sunday, U.S. and South Korean officials said, a high-profile failure that comes as a powerful U.S. aircraft supercarrier approaches the Korean Peninsula in a show of force.

It wasn’t immediately clear what kind of missile was test-fired from the east coast city of Sinpo. But the failure will sting in Pyongyang because it comes a day after one of the biggest North Korean propaganda events of the year— celebrations of the 105th birthday of late North Korea founder Kim Il Sung, the current leader’s grandfather.

The North’s test firing can be seen as a message of defiance to the Trump administration in Washington, coming as it does on the day U.S. Vice President Mike Pence is set to arrive in Seoul for talks on North Korea.