(ATTN: UPDATES throughout with S. Korean military's analysis; RECASTS headline, lead)
By Song Sang-ho
SEOUL, Jan. 14 (Yonhap) -- North Korea fired two suspected ballistic missiles eastward Friday, South Korea's military said, after Pyongyang publicly warned earlier in the day of a "stronger and certain" response to the United States' imposition of new sanctions.
The North launched the "short-range" projectiles from a site in North Pyongan Province, a northwestern region bordering China, the Joint Chiefs of Staff (JCS) said in a text message sent to reporters. It did not elaborate.
The North's latest saber-rattling marks its third show of force this year.
South Korea's military is monitoring related North Korean movements and maintaining a firm readiness posture, the JCS said.
Earlier in the day, Pyongyang issued the warning after Washington slapped the sanctions on six North Koreans involved in the regime's weapons of mass destruction and ballistic missile programs Wednesday.
"If the U.S. adopts such a confrontational stance, the DPRK will be forced to take stronger and certain reaction to it," a spokesperson of the foreign ministry said in a statement carried by the North's official Korean Central News Agency. DPRK stands for the North's official name, the Democratic People's Republic of Korea.
The North fired what it claims to be hypersonic missiles on Jan. 5 and Tuesday, in an apparent quest for new advanced weapons amid a deadlock in nuclear talks with the United States.