This photo released by the North Korean government shows what it says was a test launch of a hypersonic missile on Jan. 11. AP-Yonhap

By Nam Hyun-woo

North Korea launched projectiles assumed to be short-range ballistic missiles on Friday, just three days after it tested what it claimed was a hypersonic missile.

The launch came hours after Pyongyang threatened "a stronger reaction" against a fresh set of sanctions imposed by the United States over its recent tests of hypersonic missiles, showing that North Korea is taking a stance of "action for action."

According to Seoul's Joint Chiefs of Staff (JCS), the military observed two projectiles launched from North Pyongan Province to the eastern side of the North on Friday afternoon. The JCS added that the projectiles are assumed to be short-range ballistic missiles.

Friday's launch marked the North's third missile test of this year. On Jan. 5, the regime launched what it claimed was a hypersonic missile capable of flying at five times the speed of sound, followed by the launch of a more advanced version six days later, which is assumed to have traveled at 10 times the speed of sound.

In the previous two tests, North Korea launched the hypersonic missiles from Jagang Province, which is located in the central northern part of its territory.

On Friday, however, the regime fired the missiles from North Pyongan Province, located in the northwestern corner of the country. Citing this aspect, experts said that the missiles would not be hypersonic ones, and that the launch was conducted "out of North Korea's weapons development schedule," which is aimed at showing "its military capability."

"When North Korea tests a new missile, the regime typically launches it in the early morning, in order to make it difficult to be identified by other countries. However, the North fired this time in the afternoon, meaning that the launch is aimed at warning the U.S. rather than testing new technologies," said Cheong Seong-chang, the director of the Center for North Korean Studies at the Sejong Institute.

The launch came hours after a spokesperson of North Korea's foreign ministry threatened "a stronger and certain reaction" to the U.S. sanctions.

In the statement carried by the state-run Korean Central News Agency, the spokesperson said, "The DPRK's recent development of new-type weapons was just part of its efforts in modernizing its national defense capability. It did not target any specific country or force and it did not do any harm to the security of neighboring countries." DPRK stands for North Korea's official name, Democratic People's Republic of Korea.

"The U.S. accusation of the DPRK's legitimate exercise of the right to self-defense is an evident provocation and a gangster-like logic. … If the U.S. adopts such a confrontational stance, the DPRK will be forced to take a stronger and certain reaction to it."

On Wednesday (EST), the U.S. sanctioned six North Koreans for their involvement in procuring goods for the regime's missile program, and proposed additional United Nations Security Council sanctions on North Korea.

The U.S. move was interpreted as a response to North Korea's continued missile threats and intention to show that Washington will also deal with North Korea with a stance of "action for action."

"The launches on Jan. 5 and 11 were interpreted as North Korea's planned missile test, as the regime needs to avoid weapons tests during the Beijing Winter Olympics, which China seeks to portray as an instrument of peace," Cheong said. "On the other hand, Friday's launch of short-range ballistic missiles shows the North's clear intention that it will escalate military tensions on the Korean Peninsula if the U.S. remains hostile to it."