North Korea has successfully completed testing its newly developed "cutting-edge ultra-precision tactical guided missiles," state-run KCNA reported Friday, adding that the tests were overseen by leader Kim Jong Un, amid claims by South Korean officials that the North had carried out fire drills in its direction.

The hermetic North fired three projectiles off its east coast, which then flew about 118 miles before landing harmlessly in the Sea of Japan, media reports said, citing South Korean defense officials Thursday. While the North did not reveal further details about the tests, they could be related to the projectiles that the South claimed were fired toward the Sea of Japan, also known as the East Sea, because there were no other test-firing drills reported in recent days, according to Associated Press, or AP.

“The guided missiles soared into the sky with a thunderous roar,” KCNA reportedly said. “The test-fire clearly proved that the tactical guided weapons didn’t have an inch of deviation in their scientific and technological performance.”

South Korean defense ministry spokesman Kim Min-seok said, at a briefing, according to Bloomberg: “From North Korea’s point of view, it may be a new weapon, but compared to the international trend, it’s already been developed."

According to reports, South Korean officials are investigating the exact nature of the projectiles that were fired.

“It’s still unclear if North Korea test-fired new weapons, or launched them for intentional provocation,” a spokesman told Agence France-Presse, or AFP, according to Defense News.

The South Korean defense spokesman also reportedly said Friday that North Korea’s latest test was to upgrade its large-caliber multiple rocket launching system, or MRL. "The MRL ranges have been extended and guidance capabilities added to the projectiles," the spokesman said, according to AFP.

According to AP, North Korea’s official media outlet called the latest missile launches “significant” because they were made at a time when the North, which has claimed that the U.S. and South Korea are “going extremely reckless in the moves to isolate and stifle (North Korea) and unleash a war of aggression,” has been attempting to strengthen its arsenal.

While short-range test firings by North Korea are reportedly not uncommon, military tension between the two Koreas has elevated over missile and artillery tests conducted earlier this year.

U.S. state department spokeswoman Marie Harf said, according to AFP: “Technically, obviously any launch of anything is problematic, is escalatory in nature, is threatening."