(SEOUL) North Korea confirmed it fired a “new type” of solid-fuel intercontinental ballistic missile (ICBM) on Thursday, a first for the country, according to South Korea’s Yonhap news agency.

According to Yonhap, North Korean leader Kim Jong-un said the test marks a major technological breakthrough for the country’s weapons program.

All intercontinental ballistic missiles (ICBMs) launched so far by North Korea have been liquid fueled. However, solid-fuel missiles, which Pyongyang has long sought to develop, are more stable and faster to prepare, which makes it more difficult for the enemy to detect and destroy them.

This “new type of ICBM is a rapid advance in nuclear counterattack,” Kim Jong-un said, according to Yonhap.

The South Korean military said Thursday that North Korea had “launched a new type of ballistic missile, possibly solid-fuelled.”

At a military parade in Pyongyang in February, North Korea showed off a record number of missiles, including what analysts believe is a new solid-propellant ICBM.

The announcement comes on the eve of one of the most important political anniversaries celebrated in North Korea, “Day of the Sun”, April 15.

This date is the birth anniversary of North Korea’s founding leader, Kim Il-sung, and is usually celebrated with significant weapons trials or military parades.