After his historic trip to Russia, North Korean leader Kim Jong Un is mapping out further steps to boost ties with Russia, state media KCNA reported on Friday.

The move comes despite pushback from South Korea and the United States, which have threatened serious consequences if Pyongyang and Moscow cooperated on arms trade.

During Kim's weeklong trip, the North Korean leader and Russian President Vladimir Putin agreed to improve military and economic cooperation between the two countries.

At a meeting of the ruling Workers' Party's politburo on Wednesday, Kim decided to take steps for developing ties with Moscow at "a new high level at the practical stage" to consolidate "the success" of his Russia trip.

Concerns over arms trade

The negotiations between Russia and North Korea have raised concern in South Korea and the US. Officials say that Russia is trying to refill its ammunition stocks from North Korea, while Pyongyang is seeking technological help for enhancing its nuclear and programs.

Experts say that Russia and North Korea likely discussed banned arms transfer deals during Kim's trip.

Leaders of the two countries have declared that they will cooperate on defense strategies but they have not shared details of their cooperation, leaving Seoul and Washington concerned.

South Korea issues new sanctions

Seoul, on Thursday, imposed new sanctions against 10 individuals in relation to North Korea's nuclear activities and arms trade with three countries, including Russia.

Seoul's decision to impose new sanctions came after South Korean President Yoon Suk Yeol had warned the United Nations on Wednesday about the potential arms deals with Pyongyang.

Yoon said that if Russia assists North Korea in its weapons program then it would be a "direct provocation."

The sanctions have been issued for 10 people which also include North Korea's defense minister and the chief of staff of its military, South Korea's foreign ministry said on Thursday.

South Korean President Yoon Suk Yeol had also accused North Korea of violating UN Security Council sanctions, at the UN General Assembly in New York. 

Hinting at Russia — a signatory to the UN resolutions against North Korea and a permanent UN Security Council (UNSC) member — Yoon said that it will be paradoxical for a permanent member of the UNSC, to invade another sovereign country while receiving "arms and ammunition from a regime that blatantly violates" security council resolutions.

South Korea and the US have warned of serious consequences if Russia and North Korea breach UNSC resolutions. 

mfi/rs (Reuters, AP, dpa)