North Korea fired more than 20 missiles on November 2, including one short-range ballistic missile that crossed the Northern Limit Line, prompting a rare warning for residents of South Korea's Ulleungdo island to seek shelter in bunkers.

Seoul's military said at the time it was the "first time since the peninsula was divided" at the 1953 end of Korean War hostilities that a North Korean missile had landed so near the South's territorial waters.

Shortly after, South Korea dispatched a salvaging vessel to search for the missile, which landed in waters some 5,000 to 6,500 feet deep (1,500 to 2,000 meters), Seoul-based specialist site NK News reported.

On Wednesday, the defence ministry said in a statement that it had successfully retrieved a three-meter-long, two-meter-wide piece of debris, which it identified as a North Korean SA-5 missile.

"The SA-5 is a missile that can also be used as a ground-to-ground missile," it said.

"Russia recently used a similar ground-to-air missile as a ground-to-ground missile in the Ukraine war," the statement added.

The announcement comes a day after Pyongyang denied US claims that it was covertly providing artillery ammunition to Moscow for its war in Ukraine.

Last week, White House national security spokesman John Kirby said North Korea was supplying "a significant number of artillery shells" to Russia under cover of shipments to the Middle East or Africa, adding it was not clear whether Moscow had received them.

Earlier this month, Pyongyang carried out a record-breaking blitz of weapons launches -- including an intercontinental ballistic missile -- in response to the biggest-ever joint air drills by Seoul and Washington.

The United States and South Korea have warned that such missile launches could culminate in a nuclear test by North Korea.