Apr 02, Kathmandu- North Korea on Tuesday launched a medium-range ballistic missile. South Korea, the United States and Japan conducted a joint air exercise involving nuclear-capable B-52H bombers a few hours later.

Pyongyang's latest launch comes less than two weeks after North Korean leader Kim Jong-un oversaw the testing of a solid-fuel engine for a new intermediate-range hypersonic missile (IRBM).

According to the South Korean military, the missile launched on Tuesday morning flew about 600 kilometers before falling in the waters between South Korea and Japan.

The Joint Chiefs of Staff said that the military was analyzing the launch. The Yonhap news agency quoted a defense official as saying it may have included the "hypersonic warhead" used in the engine launch last month.

North Korea has been trying to achieve breakthroughs in advanced hypersonic and solid fuel technology for a long time. Attempts have been made to make these missiles capable of threatening US regional military bases by challenging the South Korean-US missile defense system.

In January, Pyongyang said it had launched a solid-propellant 'IRBM' with a hypersonic warhead. Then, last month, a successful engine test of a 'new type of intermediate-range hypersonic missile' was conducted.

Hypersonic missiles can be operated in fast and mid-flight. Because they are difficult to control and intercept, solid-fuel missiles do not require fuel before launch. It is difficult to find and destroy those missiles that are considered ready to use.

Seoul's Defense Ministry held a joint air exercise with Washington and Tokyo on Tuesday. These include nuclear-capable B-52H bombers and F-15K fighter jets near the Korean Peninsula.

The purpose of this exercise is to "improve joint preparedness against the North's nuclear and missile threats," the source said.

Given the sensitive nature of the weapon, he said, Kim is developing such technology domestically rather than with Russian help.

The launch comes days after a Russian veto at the United Nations ended a UN expert's monitoring of North Korean sanctions violations amid an investigation into alleged arms transfers between Moscow and Pyongyang. North Korea has not yet commented on this development.

The launch is a week before voting in South Korea's general election. In which President Yoon Suk Yeol's party, which has taken a hard line with Pyongyang, is trying to re-strengthen its grip on the parliament.