North Korean leader Kim Jong Un participated in training exercises with troops involving a new tank model, even taking the helm himself, state media reported Thursday, as his rivals South Korea and the U.S. concluded their yearly military drills.

It's the third time Kim was reported to have observed military exercises since the start of the 11-day South Korean-U.S. drills, which he views as rehearsals for an invasion. That's a less provocative option than missile tests. North Korea has intensified launches since 2022 and ramped up belligerent rhetoric this year.

At the tank drills Wednesday, Kim praised the country's latest tank as "the world's most powerful" and told his troops to bolster their "fighting spirits" and complete "preparations for war," according to the official Korean Central News Agency (KCNA). The other two drills he inspected recently were dedicated to artillery firing and maneuvering exercises.

The tank was first unveiled during a military parade in 2020, and its rolling during Wednesday's drill indicates that it's ready to be deployed, South Korean experts say.

Photos of the tank released by North Korea show it has a launch tube for missiles, a weapons system the former Soviet Union already operated in the 1970s. The new tank could pose a threat to South Korea, said Yang Uk, an analyst at Asan Institute for Policy Studies, but it remains to be seen whether it can be mass produced.

The North's Defense Ministry last week threatened "responsible military activities" in reaction to the South Korea-U.S. military drills, which involved a computer-simulated command post training and 48 kinds of field exercises, twice the number conducted last spring. The U.S. and South Korea have been expanding their training exercises in a tit-for-tat response to the North's weapons testing spree.

Concerns about North Korea's military preparations have deepened since Kim vowed in a speech in January to rewrite the constitution to eliminate the country's long-standing goal to seek peaceful unification of the Korean Peninsula and cement South Korea as its "invariable principal enemy." He said the new constitution must specify North Korea would annex and subjugate the South if another war broke out.

Kim's moves signal "North Korea's fundamental change on its South Korea policy, beyond just rhetoric," as the North's previous push for inter-Korean unity had allowed it to make a steadfast call for the removal of U.S. troops in South Korea, a senior South Korean presidential official told a small group of reporters Monday. He requested anonymity, citing the delicate nature of the issue.

Observers say Kim likely wants to use his upgraded weapons arsenal to win U.S. concessions like extensive relief of international sanctions on North Korea. They say North Korea is expected to extend its testing activities and ramp up warlike rhetoric this year as South Korea holds parliamentary elections in April and the U.S. a presidential election in November.

"The South Korean-U.S. training is over, but the North's isn't over yet," Yang said. "They won't just stand still ... they've been talking about war."