Russia's President Vladimir Putin, right, and North Korea's leader Kim Jong-un attend a meeting at the Vostochny Cosmodrome in the Russian Far East, in this Sept. 13, 2023, file photo. Amid concerns over growing ties between the two countries, experts said on Monday that Moscow will likely tread carefully when it comes to signing a new defense treaty with Pyongyang. Reuters-Yonhap

Concerns have been rising over how far Pyongyang's ties with Moscow would go since North Korea's state media called for reinforcing the partnership based on a "new legal foundation" last month.

Ahead of Russian President Vladimir Putin's possible visit to the North Korean capital, some worry the foundation could mean the revival of a defense treaty between the two countries ― one under which one party must intervene militarily in support of the other in the event of a war.

After signing such a mutual defense treaty in 1961, the two countries had maintained it for 35 years until 1996, when it was abrogated after years of diplomatic efforts by South Korea.

Analysts contacted by The Korea Times on Monday said the chances of the two sides inking such a high-stakes deal are slim. Putin, they said, has much more to lose than gain by siding officially with Kim Jong-un, North Korea's ill-famed leader.

"Putin, who desperately needs North Korea's continuous support for his war in Ukraine, will likely offer something Kim would like if he visits Pyongyang. But I think it won't be a defense treaty," Chung Eun-sook, a Russia expert at the think tank Sejong Institute, said.

"Kim would seek stronger military ties with Russia and frame the current geopolitical situation as a new Cold War. But Russia knows that's against its national interest in the long term. It just needs North Korea's ammunition and shells."

Despite plenty of evidence of having used North Korean weapons in its war efforts, Moscow has denied that it violated U.N. Security Council resolutions, which prohibit all forms of arms trade with Pyongyang.

This shows the Kremlin's consistent diplomatic strategy of denial and suggests it is not keen to make its own admission of their hidden trade by signing a defense treaty, according to Cho Han-bum, an analyst at the Korea Institute for National Unification (KINU), a state-funded think tank.

"Unlike the Cold War era, during which Russia was one of only two dominant countries in de facto two separate worlds, Russia now belongs to the single global supply chain system and cannot leave it," Cho said. "The war has brought Russia and North Korea closer. Yet, the war is not going to last forever. When it ends, Russia will find North Korea much less useful."

But as long as the war continues, North Korea will remain the Kremlin's crucial partner. With the armed conflict showing no signs of abating, Putin could respond favorably to Kim's calls to upgrade the current "friendship treaty," Hyun Seung-soo, another analyst at the KINU, said.

"A likely scenario would be adding a clause with much room for interpretation to that treaty ― with stronger terms that can highlight Russia's possible help for North Korea in the case of a war [with South Korea or the United States]," he said.

At a U.N. Security Council briefing on the Ukraine issue at U.N. headquarters in New York on Friday local time, Cho Tae-yul, South Korea's foreign minister, expressed concerns over the North's suspected military collaboration with Russia.

"If and when it turns out to be the case that North Korea receives in return, whether advanced military technology or oil shipments exceeding limits under Security Council resolutions, this would redound to North Korea's ability to threaten security on the Korean Peninsula and beyond," he said.