North Korea fired off a barrage of at least 23 missiles of various types from its east and west coasts on Wednesday, including one that landed near South Korean territorial waters for the first time since the 1953 division of the peninsula, pushing tensions to fresh highs.

South Korean President Yoon Suk-yeol slammed the North's launches as "effectively a violation of our territory," his office said in a statement as he called on the military to remain on guard for additional "high-intensity provocations" — a likely reference to even more missile launches or an anticipated seventh nuclear test by the North.

The South Korean military later said the North had also fired around 100 rounds of artillery into a military "buffer zone" off its east coast.