North Korea’s latest round of missile tests and military exercises did not provoke or threaten the United States, the U.S. Chairman of the Joint Chiefs of Staff said on Tuesday at the Pentagon.

Instead, said General Mark Milley, the country may have been marking a “celebration.”

Milley did not specify which celebration he meant, but the birthday of Kim Il Sung — the late founder of the DPRK and grandfather of current North Korean leader Kim Jong Un — is on Wednesday. The so-called Day of the Sun is a national holiday in the North