North Korea has once again launched a missile in South Korea. South Korea’s Joint Chiefs of Staff confirmed the launch Sunday morning but did not provide further details.

Three days after the launch, North Korea said it had tested a solid-fuel motor for a new strategic weapon. It is said that North Korea has developed an intercontinental ballistic missile that can reach the US mainland.

In recent months, North Korea has been testing a barrage of nuclear-capable ballistic missiles, most recently developing its longest-range, liquid-fueled Hwasong-17 ICBM designed to carry multiple warheads. Experts say North Korea is finally using its expanded arsenal to seek sanctions relief and other concessions from the United States.

Seoul’s military said North Korea launched an “unidentified ballistic missile” on Sunday, hours after Pyongyang announced it had successfully tested a solid-fuel motor. South Korea’s Joint Chiefs of Staff said North Korea had fired an unidentified ballistic missile into the East Sea.