North Korea says it tested two “strategic cruise missiles” from a submarine for the first time on Sunday in a demonstration to the U.S. and South Korea of the country’s “diverse” nuclear strike methods, as the allies kick off large-scale joint drills.

State media said the “underwater launching drill” off the east coast serves as “proof of the regular operating posture of [our] nuclear war deterrent means in diverse spaces.” The report did not mention the presence of leader Kim Jong Un at the test.