SEOUL – North Korea warned South Korea on Friday to cancel artillery drills planned for the same island the North shelled in November, pledging it would answer any provocation with a strike even harsher than last month’s deadly attack.

Sometime between today and Tuesday, Seoul plans a live-ammunition drill on Yeonpyeong Island, where similar drills on Nov. 23 prompted an artillery barrage from the North that killed four people.

The North’s state-run Korean Central News Agency reported Friday that officials in Pyongyang sent a notice to Seoul warning that further drills on the island would bring “unpredictable self-defensive strikes.” The notice added that “the intensity and scope of the strike will be more serious than the Nov. 23” shelling, the news agency said.

North Korea dismissed the drills as an effort to “save the face of the South Korean military, which met a disgraceful fiasco” in the shelling of Yeonpyeong, the news agency said.

But South Korea pledged on Friday to carry out the exercises, which Defense Ministry officials characterized as part of “routine, justified” exercises for its own defense.

Many fear that the newest belligerence from North Korea may signal a possible slide closer to war on the peninsula.

“What you don’t want to have happen out of that is for us to lose control of the escalation,” Gen. James Cartwright, vice chairman of the U.S. Joint Chiefs of Staff, told reporters in Washington.

The Obama administration has supported Seoul’s planned drills, saying they posed no threat to the North. “North Korea should not see these South Korean actions as a provocation,” State Department spokesman P.J. Crowley said Thursday.

But in Moscow, Russian Deputy Foreign Minister Alexei Borodavkin summoned U.S. and South Korean envoys Friday to urge the South “to refrain from the planned firing to prevent further escalation of tension in the Korean peninsula,” according to a ministry bulletin.

“I think these plans are counterproductive and very dangerous,” Andrei Klimov, deputy head of the foreign relations committee in the lower house of the Russian parliament, said in an interview. “You simply can’t scare these . . . fanatics with a mere demonstration of force or, in other words, with a provocation like this.”

The most recent back and forth between the Koreas came as New Mexico Gov. Bill Richardson arrived in Pyongyang on a private mission to try to ease tensions, which have been heightened since North Korea allegedly torpedoed a South Korean patrol ship in March, killing 46 crewmen.

Richardson, who has in the past served as unofficial envoy to North Korea, planned a four-day visit that reportedly included a tour of the North’s main nuclear complex at Yongbyon.

U.S. officials stressed that Richardson, who was invited to North Korea, was not acting in any official capacity. But many analysts hoped that his talks with officials there might help persuade the North to finally give up its nuclear weapons program.