North Korea launched approximately 10 short-range ballistic missiles toward the sea on Thursday, the South Korean military announced, one day after North Korea had rejected a U.S. decision to decrease the scope of joint military drills.

The Joint Chiefs of Staff stated the launches originated from the capital region around 5 p.m. local time and were directed toward North Korea's eastern waters.

South Korea has heightened its surveillance and is coordinating information on the launches with the United States and Japan. The nation's presidential national security council convened an emergency meeting to address the situation and subsequently issued a statement urging North Korea to cease ballistic missile launches, which are prohibited by United Nations Security Council resolutions.

The Japanese prime minister's office also confirmed detecting a suspected missile launch.

These launches follow the announcement Wednesday by the South Korean and U.S. militaries to scale back their 11-day Ulchi Freedom Shield exercises. President Donald Trump had previously ordered the Pentagon to "substantially reduce" the drills, citing his relationship with North Korean leader Kim Jong Un and South Korea's stance on the war in Iran.

Kim Yo Jong, the influential sister of Kim Jong Un, dismissed Trump's overture on Wednesday, stating it was not worthy of comment and that the "provocative, aggressive nature of the drills won’t change even though their duration and size were reduced." She added that if the U.S. believes this reduction signals good faith, "they will not get the desired answer."

Kim Yo Jong also referenced other military drills conducted by the U.S. and South Korea earlier in the year, as well as South Korea's pursuit of nuclear-powered submarines. Despite her critical remarks, she refrained from the typical fiery rhetoric often associated with North Korea's reactions and noted that personal relations between her brother and Trump remain "still excellent."

This stance suggests North Korea may be waiting for more significant concessions from the U.S. before returning to diplomatic talks. Kim Yo Jong denied Trump's assertion that Kim Jong Un had responded to his request for a conversation. When questioned by reporters on Wednesday, Trump expressed confidence in meeting Kim Jong Un this year and indicated he gets along well with the North Korean leader, though he did not confirm whether they were exchanging letters.