SEOUL, South Korea (AP) — North Korea fired several short-range ballistic missiles toward the sea Wednesday in its second launch event in two days, South Korea’s military said, hours after a senior North Korean official released crude insults against Seoul’s hopes for warmer relations.

South Korea’s Joint Chiefs of Staff said the missiles lifted off from North Korea’s eastern coastal Wonsan area and flew about 240 kilometers (150 miles) each in a direction toward the North’s eastern waters. It said South Korea maintains a readiness to repel any provocations by North Korea under a solid military alliance with the United States.

Seoul later said North Korea fired an additional ballistic missile toward its eastern waters without giving further details.

The South Korean military said it had also detected the launch of an unidentified projectile around North Korea’s capital region Tuesday. It said South Korean and US intelligence authorities were analyzing details of Tuesday’s launch.

South Korean media reported the previous projectile, also likely a ballistic missile, disappeared from South Korean military radars after displaying an abnormal development in the initial launch stage. This indicated the launch ended in a failure, according to the reports.

The back-to-back launches came after North Korea made it clear that it has no intentions of improving ties with South Korea, whose liberal government has steadfastly expressed its hopes to restore long-dormant dialogue.

On Tuesday night, Jang Kum Chol, first vice minister at Pyongyang’s Foreign Ministry, said South Korea would always remain the North’s “most hostile enemy state.” He derided South Korea as “world-startling fools” engaged in wishful thinking over a recent statement by Kim Yo Jong, the influential sister of North Korean leader Kim Jong Un.

After South Korean President Lee Jae Myung expressed regret over alleged civilian drone flights into North Korea, Kim Yo Jong late Monday praised him for what she called honesty and courage, but reiterated a threat to retaliate if such flights recur. South Korean officials responded by describing Kim Yo Jong’s statement as meaningful progress in relations.

Jang said her statement was intended as a warning. He cited Kim Yo Jong as calling South Korea “the dogs affected by mange that blindly bark to the tune of neighboring dogs” as she criticized it for recently co-sponsoring of a UN human rights resolution on the North’s purported human rights violations.

North Korea has refused to return to talks with South Korea and the US and pushed to expand its nuclear arsenal since Kim Jong Un’s diplomacy with US President Donald Trump collapsed in 2019. In a ruling Workers’ Party congress in February, Kim Jong Un threatened to destroy South Korea, if provoked. He left open the door for dialogue with Trump but urged Washington to drop demands for the North’s nuclear disarmament as a precondition for talks.

Earlier this week, North Korea said Kim Jong Un had observed a test of an upgraded solid-fuel engine for weapons and called it a significant development boosting his country’s strategic military arsenal.

Missiles with built-in solid propellants are easier to move and conceal their launches than liquid-fuel weapons, which in general must be fueled before liftoffs and cannot last long.

South Korea’s spy agency told lawmakers Monday the engine test was likely related to an effort to build a more powerful solid-fuel intercontinental ballistic missile that can carry multiple nuclear warheads, according to lawmakers who attended the meeting.

Experts say North Korea needs multi-warhead missiles to penetrate through US missile defenses, but doubts the country has mastered a technology needed to acquire such a weapon.