North Korean leader Kim Jong Un is warning that his country is developing “overwhelming military power that cannot be stopped,” just days after the secretive state conducted its largest-ever test of an intercontinental ballistic missile, state-run media reported Monday.

Kim made the comments during a photo session over the weekend with the defense industry team behind the launch of the Hwasong-17 ICBM, which North Korea says it test-fired on Thursday.

The launch was the first time Pyongyang fired a long-range missile since 2017, ending a self-imposed moratorium on ICBM tests.