SEOUL — North Korea’s leader Kim Jong-un may have another more immediate reason for conducting all those missile tests aside from the desire to intimidate South Korea and its American ally.

“It’s possible,” South Korea’s defense minister, Shin Won-sik, believes, that “they are testing new weapons for sale to the Russians.” The possibility emerges as North Korea counts on Moscow to respond to the export of North Korean arms and ammunition by increased shipments of food to feed the North’s hungry people.

Mr. Shin spoke out in a rare parley with correspondents here hours after North Korea fired five short-range missiles off its east coast in apparent response to American and South Korean joint military exercises that wrapped up three days earlier. The missiles, with a range of about 300 miles, were said to be similar to a solid fuel model fired in January and capable of carrying a nuclear warhead to targets anywhere in South Korea and in most of Japan.

It’s not certain if they’re ready for export, but Mr. Shin said North Korea by now has shipped 7,000 containers of arms to Russia since Mr. Kim and President Putin met at the Cosmodrome in Siberia in September. They’re presumed to be laden with artillery shells badly needed by the Russians as well as cruise missiles. Solid-fuel missiles can be fired almost immediately after getting to a launch site unlike liquid-fuel missiles into which the fuel is pumped on the site within view of satellite eyes in the sky.

A retired army general, Mr. Shin responded with contempt to Mr. Kim’s rising rhetoric. Reflecting the widespread view of American as well as South Korean officials, he obviously did not believe North Korea posed a serious threat to the South, at least not now.

“They’re going through regime instability,” he said. “They’re doing it mainly to maintain regime solidarity” – that is, to impress the North’s hungry people at a time of what’s believed to be simmering if hidden discontent with Mr. Kim’s rule.

Mr. Shin, speaking not only for himself but for the South’s conservative President Yoon Suk-yeol, was not impressed by Mr. Kim’s declaration that the North henceforth would have absolutely nothing to do with the South.

“North Korea has said they are going to completely stop relations with South Korea,” he said. “I don’t believe that’s really the truth. North Korea is making provocations in the context of military exercises.” However, he noted, the North avoided “provocations” during the American-South Korean exercises. “They saw they have nothing to gain.”

He also viewed almost with amusement the reconnaissance satellite that North Korea has launched. “It’s not getting anything done,” he said. “It is not serving reconnaissance capabilities.” All the North was capable of doing, he said, was to change altitude of the satellite, moving it up and down in orbit.

Clearly, however, the North’s rising shipment of armaments to the Russians was a matter of much greater concern. The containers are moving by rail across the North’s 11-mile frontier with Russia and also by ships that unload them at Russian railheads in Siberia, from which they move by rail across Russia to Ukraine.

As for South Korea shipping armaments to Ukrainian forces, Mr. Shin insisted the South has no immediate intention of doing so. South Korea’s aid for Ukraine is strictly “non-lethal,” including medicine, he said, and he foresaw no “red line” after which the South might change its policy. He acknowledged, however, that South Korea has been shipping shells to replenish America’s supply while Washington ships its own shells to Ukraine.

Mr. Shim was more concerned about the North’s nuclear weapons than about the immediate possibility of attack. “It is a very tense atmosphere this year,” he said, but he evinced no doubt about the American alliance. “If North Korea is advancing nuclear capabilities,” he said, “both South Korea and America will be increasing military exercises.” If Mr. Kim carries out his rhetorical threats, he added, “we are going to make a strong counter-attack.”