"The North Korean nuclear issue could never be resolved through war. That's impossible," Song also quoted Putin as saying during their 45-minute meeting in Moscow. "The problem should be solved through dialogue because using sanctions alone has limitations, and it could also work against North Korean people and incur humanitarian issues."

The president also stressed the need to resume the forum of the six concerned countries, known as the six-party talks, to negotiate ways to deal with the North Korean issue as well as the need to open direct talks between North Korea and the United States.

Putin said he will hold a phone conversation with US President Donald Trump to talk him into resuming dialogue with Kim Jong-un, according to Song, a lawmaker of the ruling Democratic Party.

Touching on South Korea's staging of the US-built Terminal High Altitude Area Defense (THAAD) system, Putin reiterated Russia's opposition.

"The THAAD system has limits in its effectiveness to fend against North Korea's long-range artillery. ... The problem of (North Korean nuclear and missile development) cannot be resolved by military responses only," Putin was also quoted as saying.

Also discussed in the meeting were several trilateral economic cooperation projects involving the two Koreas and Russia, which were suspended in early 2016 following North Korea's nuclear tests and missile provocations. They include the trilateral logistics project aimed to link the three countries' sea ports to transport Russian coal to South Korea via North Korea.

Putin expressed intentions to resume those economic projects, stressing that such joint work could help resolve tensions on the peninsula.

They shared the understanding that South Korea needs to make efforts to pursue trilateral economic projects and agreed to discuss the issue further during a future summit between Moon and Putin.

A free trade agreement between South Korea and the Russia-led regional block, the Eurasian Economic Union, and a bilateral project to jointly develop Arctic shipping routes were also suggested during the meeting, according to Song.

Moon and Putin are set to meet in July on the sidelines of the Group of 20 meeting in Germany. Putin expressed his expectations for the summit and invited Moon to the Eastern Economic Forum that Russia is to host on Sept. 6-7.

Song conveyed Moon's handwritten letter to Putin and Moon's messages indicating that he is eager to step up bilateral relations with Russia.

With the meeting with Putin, Song wrapped up his Russian trip and plans to head back to Seoul on Thursday. (Yonhap)