North Korea fired multiple 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 several missiles lifted off from North Korea’s eastern coastal Wonsan area on Wednesday morning and flew about 240 kilometers (150 miles) each in a direction toward the North’s eastern waters. It said an additional North Korean ballistic missile fired later Wednesday traveled more than 700 kilometers (435 miles) off the North's east coast.South Korea's military said it maintains a readiness to repel any provocations by North Korea under a solid military alliance with the United States. It earlier said it detected the launch of an unidentified projectile from North Korea’s capital region Tuesday.South Korean media reported the 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 failure, according to the reports.'CREDIBLE INTELLIGENCE' REVEALS NORTH KOREA'S SUCCESSOR TO KIM JONG UN, SOUTH KOREA SAYS 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 North Korea'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.NORTH KOREAN DICTATOR SAYS GOVERNMENT WILL KEEP CEMENTING NATION'S 'IRREVERSIBLE STATUS AS A NUCLEAR POWER' 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 U.N. resolution on the North’s purported human rights violations.North Korea has refused to return to talks with South Korea and the U.S. and pushed to expand its nuclear arsenal since Kim Jong Un’s diplomacy with U.S. President Donald Trump collapsed in 2019. North Korea has instead sought to strengthen ties with Russia, China and other countries embroiled in confrontations with the U.S. Last September, Kim Jong Un traveled to Beijing to attend a military parade alongside other foreign leaders and held his first summit with Chinese President Xi Jinping in six years.North Korea’s state media said Wednesday that Chinese Foreign Minister Wang Yi will visit North Korea on Thursday for a two-day trip.NORTH KOREA TESTS SOLID-FUEL MISSILE ENGINE AS KIM BOOSTS THREAT TO US MAINLAND 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 wants multi-warhead missiles to penetrate U.S. missile defenses, but they doubt Pyongyang has mastered the technology needed to acquire such a weapon.