SEOUL, South Korea — North Korea’s military said it put all its missile and artillery units on “the highest alert” on Tuesday, ordering them to be ready to hit South Korea, as well as the United States and its military installations in Hawaii and Guam.

The threat from the North’s Korean People’s Army Supreme Command came only hours after President Park Geun-hye of South Korea warned that the North Korean leadership could ensure its survival only when it abandons its nuclear weapons, long-range missiles, provocations and threats.

North Korea said on Tuesday that all of its strategic rocket and long-range artillery units “are assigned to strike bases of the U.S. imperialist aggressor troops in the U.S. mainland and on Hawaii and Guam and other operational zones in the Pacific as well as all the enemy targets in South Korea and its vicinity.”

“They should be mindful that everything will be reduced to ashes and flames the moment the first attack is unleashed,” the North Korean command said in a statement carried by the North’s official Korean Central News Agency.