"If that happens, we will take decisions that will not please South Korea's current leadership," Putin said during a visit to Vietnam on Thursday.

The South Korean government previously expressed concern over the new Russia-North Korea strategic partnership that includes a pledge of mutual assistance if either country is attacked.

Seoul said the security commitments violated UN sanctions imposed on Pyongyang.

It also suggested that it might reconsider its long-term policy of not supplying arms to Kiev.

North Korea, ruled by President Kim Jong Un, is subject to far-reaching United Nations sanctions and import restrictions due to its nuclear weapons program, including on arms trade and the transfer of military technologies to the country.

Putin signed the partnership agreement with Kim during a state visit to Pyongyang on Wednesday.

At a press conference in Hanoi on Thursday, Putin dismissed Seoul's concerns as baseless.

He said South Korea had nothing to fear because the treaty would come into force only if Russia or North Korea were attacked by a third country.

"As far as I know, (South Korea) is not planning any aggression against North Korea," he said.

This means that "there is no need to fear our cooperation".

Putin also said that he would not deploy any North Korean troops in Ukraine.

However, he threatened to supply high-precision weapons to North Korea in response to Western arms deliveries to Ukraine.



int/khz