SEOUL, South Korea >> North Korean leader Kim Jong Un ordered unspecified steps to further develop relations with Russia after his recent visit to the country as his foreign rivals warn that any cooperation on military weapons would be dangerous and bring consequences.

Experts speculated North Korea and Russia likely discussed banned arms transfer deals and other cooperation measures during Kim’s six-day trip last week. They say the two countries are serious about sharply boosting their ties while they are engaged in separate confrontations with the West.

During a Politburo meeting on Wednesday, Kim arranged for work to be done on further developing bilateral ties at “a new high level at the practical stage” to consolidate “the success” of his Russia trip, the official Korean Central News Agency said Friday.

Kim underscored the need to expand bilateral cooperation in every field, making a substantial contribution to the promotion of the well-being of the people of the two countries, KCNA said.

While traveling in Russia’s Far East, Kim met with President Vladimir Putin and visited key Russian military and technology sites. The two suggested they would cooperate on defense issues but gave no specifics, which left South Korea and its allies — including the United States — uneasy.

Observers say Kim could ship ammunitions to refill Putin’s exhausted arms stores to back his war efforts in Ukraine in return for receiving sophisticated weapons technologies and economic aid.

The U.S., South Korea and their partners have warned that Russia and North Korea would pay a price if they proceed with such deals in breach of U.N. Security Council resolutions that ban any weapons trade with North Korea. Russia, a permanent member of the U.N. Security Council, voted for those U.N. resolutions.

Speaking before the U.N. General Assembly on Wednesday, South Korean President Yoon Suk Yeol said any action by a permanent U.N. Security Council member to circumvent international norms would be dangerous and “paradoxical.” Yoon said that South Korea, together with its allies, “will not sit idly by” over a possible Pyongyang-Moscow weapons deal that he said would pose a threat to not only Ukraine but also South Korea.

Many experts say North Korea would seek Russian help to complete the development of high-tech weapons systems such as spy satellites, nuclear-powered submarines and powerful long-range missiles. They say Kim wants to modernize his weapons arsenals to wrest greater concessions from the U.S. and South Korea.