North Korea fired three ballistic missiles early on Tuesday into the sea off its east coast that had a range of between 500 and 600 kilometers (300 and 360 miles), South Korea's military said.
The missiles were launched towards east from an area in the North's western region called Hwangju from 5:45 a.m. local time to 6:40 a.m., the South's military said.
"The ballistic missiles flight went from 500 kilometers to 600 kilometers, which is a distance far enough to strike all of South Korea including Busan," the South's military said in a statement.
Busan is a South Korean port city in the south.
North Korea has test-fired a series of ballistic missiles in recent months including an intermediate-range missile in June and a submarine-launched missile this month.
Tuesday's launch came days after South Korea and the United States announced a final decision this month to deploy the Terminal High Altitude Area Defence (THAAD) anti-missile system in the South to counter threats from the North.
North Korea's military has threatened to retaliate against the deployment of the system with a "physical response" once its location and time of installation were decided.
China has also sharply criticized the decision as a move that will destabilize the security balance in the region.