North Korean leader Kim Jong Un inspected a live-fire artillery drill by his country's military units near the sea border with the rival South, believed to be timed ahead of annual U.S.-South Korean exercises, state media reported Saturday.

Analysts in Seoul said North Korea was attempting to demonstrate its military capabilities ahead of next month's U.S.-South Korean drills, which Pyongyang has condemned as a rehearsal for an invasion.

The drill, which involved artillery and anti-ship rockets, was focused on striking and capturing an enemy island, according to the North's official Korean Central News Agency. The exercise involved the Korean People's Army's 4th Corps, which led the 2010 shelling of the South Korean border island of Yeonpyeong that left four South Korean soldiers and civilians dead.

Kim expressed "great satisfaction" during the exercise and urged his army to be prepared for battle against the U.S., KCNA said. The official Rodong Sinmun published photos of Kim watching the exercise with binoculars and projectiles being fired from what appeared to be multiple rocket launchers and other weapons.

State media outlets did not disclose the exact time and location of the drill.

The U.S. and South Korea have repeatedly said that their war games are defensive in nature, and they have no intentions of attacking the North. North Korea told the United States last month that it was willing to impose a temporary moratorium on its nuclear tests if Washington scraps the military drills with South Korea this year, but the allies have refused to cancel the exercises.

North Korea routinely conducts drills in weeks prior to the U.S.-South Korea exercises and they are believed to be a significant burden for a country in desperate need of cash. Koh Yu-hwan, a professor of North Korean Studies at Dongguk University in Seoul, said that the North has been reducing the number of soldiers in the drills in recent years and is instead increasingly focusing on showcasing its newer weapons in an apparent attempt at controlling costs.

"North Korea considers it important to display its military capabilities ahead of the U.S.-South Korea drills to give its people the impression that it is well-prepared for an invasion attempt," Koh said.

South Korean Defense Ministry spokesman Kim Min-seok told reporters early this week that the U.S. was planning to send a larger number of soldiers than it did last year to the "Key Resolve and Foal Eagle" exercises beginning in early March, but did not provide a specific number.

About 12,700 American troops participated last year.