Mr Putin says late North Korean leader Kim Jong-il made no secret of the hermit nation’s nuclear arsenal during a state visit.
The Russian leader said: “In 2001, when I was on my way to pay a visit to Japan, I made a stop in North Korea, where I had a meeting with the father of the country’s current leader.
“It was back then when he told me that they had a nuclear bomb. Moreover, Seoul was within the hitting range of their standard artillery systems at that time.
“When was that? In 2001! It is 2017 already, the country has been living under permanent sanctions and instead of a nuclear bomb they have now a hydrogen bomb.”
Mr Putin said North Korea’s development of a nuclear arsenal had been provoked when North Korean bank accounts were blocked.
He also encouraged North Korea and the US to tone down the furious rhetoric and pursue diplomatic conflict resolution options.
He said: “Whatever it is, this is not my business to determine and assess the policy of the president of the United States.
“But publicly I can repeat, and I already spoke about this, all the sides should tone down their belligerent rhetoric and ways must be found for a direct dialogue between the United States and North Korea, between North Korea and the countries of the region.”
He accused US President Donald Trump of strengthening North Korean dictator Kim Jong-un’s hand through his threats of destruction.
Mr Putin admitted Russia is anxious about nuclear testing in North Korea – especially as the two countries share a border.
He said any option other than a balanced diplomatic solution would be “dangerous and dead-end”.