Russian President Vladimir Putin described North Korean leader Kim Jong Un on Thursday as an "absolutely competent and mature politician."

Kim has "accomplished his strategic objective. He has a nuclear arsenal," Putin told reporters, warning that the only way to denuclearize the Korean Peninsula is through dialogue.

North Korea has a rocket with a "range of up to 13,000 kilometers, which can reach practically any point on the globe - in any case, any point within the territory of his probable enemy," Putin said, according to state news agency TASS.

Russia and China have maintained the relatively closest diplomatic relations with insular North Korea as that country has traded threats of nuclear war with the United States.

On Wednesday, South Korea and the U.S. said they were willing to meet with North Korea - perhaps even with Kim - under some circumstances, in a potential conciliatory step after years of increasing isolation for Pyongyang.