A missile is launched from a train in an undisclosed location in North Korea, in this photo released by North Korea's state-run Korean Central News Agency, Sept. 16. North Korea fired one unidentified projectile into the East Sea on Tuesday, South Korea's Joint Chiefs of Staff said. Yonhap

North Korea fired one short-range missile into the East Sea on Tuesday, South Korea's Joint Chiefs of Staff (JCS) said, just days after Pyongyang held out the prospect of an inter-Korean summit if the South drops "double standards."

The missile was fired from the North's Mupyong-ri in Jagang Province eastward at around 6:40 a.m., the JCS said, adding the South Korean and U.S. intelligence authorities are analyzing the launch for additional information.

It did not specify if the projectile is a ballistic missile. But the Japanese government said it appears to be a ballistic missile and splashed into waters outside its exclusive economic zone, according to Japan's Kyodo News.

The launch came three days after Kim Yo-jong, sister of North Korean leader Kim Jong-un, said that Pyongyang could declare a formal end to the Korean War as suggested by the South and even discuss the possibility of a summit on conditions that Seoul drops its double standards and hostile attitudes against it.

The North has long accused South Korea and the United States of double standards, claiming it makes no sense for them to denounce the North's missile launches and other weapons tests as banned "provocations" when they are free to conduct such tests.

Tuesday's launch could be designed to test whether the South would still brand it as a provocation.

In Seoul, top security officials held an emergency security meeting of the National Security Council (NSC) and voiced regret over the launch. President Moon Jae-in ordered a "comprehensive analysis" of the missile launch and recent statements from the North, his office said.