North Korean leader Kim Jong Un pledged to bolster his regime’s nuclear weapons program during a military parade that featured displays of massive intercontinental ballistic missiles, state media reported Tuesday.

The parade was held Monday night in Pyongyang’s Kim Il Sung Square to celebrate the 90th anniversary of the army’s founding.

North Korea has conducted a flurry of weapons tests since the beginning of the year and officials in Washington and Seoul are on high alert for a nuclear test.