South Korean President Moon Jae-in left Wednesday for Vladivostok, Russia, where he will attend a regional forum and hold a series of bilateral summits with other leaders that will largely focus on how to punish North Korea for its latest nuclear test.

Following his arrival in the Russian city, the South Korean leader is set to hold a bilateral summit with his Russian counterpart Vladimir Putin, according to officials from the presidential office Cheong Wa Dae.

North Korea and its recent provocations will likely top the agenda at the one-on-one meeting, as it follows the communist state's testing Sunday of its sixth and possibly most powerful nuclear bomb.

In their earlier discussions over the phone held late Monday, Moon floated the idea of stopping oil supplies to the impoverished North, insisting it was now time to discuss the issue at the UN Security Council, according to Cheong Wa Dae spokesman Park Soo-hyun.

"It is now time to seriously review cutting off oil supplies to North Korea and ways to fundamentally block the North's cash cows, such as prohibiting countries from importing North Korean workers, at the UNSC," the South Korean leader was quoted as telling Putin.

Russia's support for such moves may put additional pressure on China, the North's strongest communist ally, which is said to account for more than 90 percent of Pyongyang's oil imports.

Putin apparently refused to offer any immediate response, only saying the North Korean nuclear issue must be resolved diplomatically.

He said the two should hold more discussions at their upcoming summit in Vladivostok, according to Park.

The Moon-Putin meeting will be followed by an expanded summit, involving some 15 other government officials from each side, at which the two countries will also seek ways to expand their economic cooperation, especially in Russia's Far East.

The two leaders are also scheduled to hold a joint press conference later in the day.

On the second day of his two-day visit, Moon will hold a summit with Japanese Prime Minister Shinzo Abe, which is also expected to focus on ways to deal with North Korea and prevent further provocations by the communist state.

They also held a telephone conversation Monday to call for new and stronger sanctions by the UNSC that will leave the reclusive North with no other choice but to come to the dialogue table.

Despite North Korea's repeated challenges to the international community, including nine missile tests since Moon took office in May, the South Korean leader continues to stress the need to engage with the North, saying there must never be another war on the Korean Peninsula.

He is currently calling for what he calls the most powerful sanctions ever against North Korea but still says the objective of such measures is to bring North Korea back to the negotiating table.

Both Russia and Japan are part of six-nation talks on ending North Korea's nuclear ambitions. The talks, also involving both Koreas, China and the United States, have been stalled since late 2008.

The South Korean president will also hold a bilateral summit with the new Mongolian president, Khaltmaagiin Battulga.

Moon will attend the third Eastern Economic Forum before returning home Thursday.

The EEF, organized and hosted by Russia, is a regional forum aimed at discussing economic cooperation for the development of the Russian Far East.

South Korean officials believe Russia's eastern Asia policy may intersect with Moon's new Northern Policy, which seeks to create a belt of economic and political cooperation with northern states, including North Korea. (Yonhap)