It also adds a chapter to the storied but often-strained friendship between Pyongyang and Moscow, which was forged in war and weathered by the Soviet collapse and tensions surrounding the North's pursuit of nuclear weapons.
A look at relations between the two sides since the 1950-53 Korean War:
The old Soviet Union was directly involved in the founding of North Korea after the end of World War II, which ended Japan's colonial rule of the Korean Peninsula but resulted in a division between the Soviet-backed North and U.S.-controlled South.
Soviet officers installed ambitious young nationalist Kim Il Sung, the grandfather of North Korea's current ruler and an ex-guerrilla commander who fought Japanese forces from Manchuria in the 1930s, as the Korean leader of the emerging state on the northern half the peninsula. By early 1950, Kim Il Sung successfully persuaded an initially reluctant Joseph Stalin to allow him to unify the Koreas by force, guaranteeing a swift victory.
Kim Il Sung's forces launched a surprise attack on the South in June, triggering a devastating war that drew massive interventions by the United States and China and left millions killed or injured before stopping with an armistice in 1953.
The Soviets supported North Korea during the war with weapons, military advisers and pilots but stayed out of land warfare, a decision that shaped Kim Il Sung's postwar efforts to strengthen his personal power and autonomy. Moscow's support became less important for Kim's internal control when he could count on China to counter the influence of the Soviets, especially after the late 1950s when relations between the two major communist powers grew increasingly hostile.
While playing Moscow and Beijing against each other to win more political independence and aid, Kim Il Sung consolidated his domestic power by violently purging his pro-Soviet and pro-Chinese opponents.
Despite the ups and downs in bilateral relations, Soviet military, energy and food aid were crucial in keeping North Korea's struggling economy afloat for decades. That all changed in 1991 with the collapse of the Soviet Union, which instantly deprived Pyongyang of its main economic and security benefactor.
The post-communist government in Moscow led by President Boris Yeltsin saw Russia as a partner of the U.S.-led West and had no enthusiasm to continue supporting North Korea with aid and subsidized trade. Moscow established formal diplomatic ties with Seoul in hopes of drawing massive South Korean investment and allowed its Soviet-era military alliance with North Korea to expire. There were widespread predictions that a collapse of the North Korean government was imminent.
Facing an existential crisis, North Korea reacted by accepting more help from China, which despite a level of mutual distrust remains Pyongyang's only major ally and considers preventing a North Korean collapse critical to its security interests. The North also became more vocal in its pursuit of a nuclear deterrent, which forced the United States to the negotiation table.
In 1994, shortly after the death of Kim Il Sung, North Korea reached a major agreement with the United States to halt plutonium production in exchange for energy and food aid and security assurances. The deal broke down in 2002 after U.S. officials confronted Pyongyang over a clandestine nuclear program using enriched uranium.
PUTIN IN PYONGYANG
Russia began to reconsider its Koreas policies in the late 1990s over what it saw as disappointing business activity with South Korea and concerns that Moscow's heavy tilt toward Seoul diminished its influence in international efforts to deal with Pyongyang. The divergence between Moscow and the West over key security issues was also becoming clear.
After his first election in 2000, Putin actively sought to restore Russia's ties with North Korea, visiting Pyongyang in July that year for a meeting with Kim Jong Il, the second-generation North Korean leader, where they issued criticism of U.S. missile defense plans. The trip was seen as Putin's message to the West that Russia would seek to restore its traditional domains of influence. Putin hosted two return visits by Kim Jong Il in 2001 and 2002.
Russia was also a participant in the so-called six-party talks with North Korea that were aimed at persuading the North to abandon its nuclear program in exchange for security and economic benefits. The talks, which also involved the United States, China, South Korea and Japan, have stalled since December 2008.
KIM'S NEW WAY
Kim Jong Un's meeting with Putin is the first summit between the countries since his father traveled to eastern Siberia for a meeting with then-Russian President Dimitry Medvedev in August 2011.
Kim Jong Il died in December that year. Under Kim Jong Un, North Korea accelerated its weapons tests to turn a crude nuclear program into a viable arsenal that includes purported thermonuclear weapons and long-range missiles potentially capable of reaching the U.S. mainland.
The Trump-Kim meeting in Vietnam in February broke down after the North demanded the removal of most of the U.S.-led sanctions against the country in exchange for a partial surrender of its nuclear program. Kim had said he would seek a "new way" if the United States continued to test his patience with sanctions.
Kim's outreach to Putin could be part of his plans to expand his options and secure allies who would apply pressure on Washington to ease its stance on sanctions. Russia currently seems better positioned to endorse Kim's stance than China, which is locked in high-stakes trade negotiations with the U.S.
The summit with Kim could also serve Putin's desire to increase Russia's regional clout. Although Moscow has never supported a nuclear-armed North Korea, it may share a view with Pyongyang that a weakened U.S. influence in the region would benefit both.
Following three-way talks in Moscow last October, the deputy foreign ministers of North Korea, Russia and China called on the U.N. Security Council to "adjust" its sanctions regime on Pyongyang to facilitate progress in the nuclear negotiations. While Moscow and Beijing can't lift the sanctions on their own, they can give Pyongyang more breathing room if Kim persuades them to loosen their enforcement of the measures.