SEOUL, South Korea >> North Korean leader Kim Jong Un inspected Russia’s nuclear-capable bombers, hypersonic missiles and an advanced warship from its Pacific fleet on Saturday as he continued a trip in Russia’s Far East that has sparked Western concerns about an arms alliance that could fuel President Vladimir Putin’s war on Ukraine.

After arriving in the city of Artyom by train, Kim traveled to an airport just outside the port city of Vladivostok where Russian Defense Minister Sergei Shoigu and other senior military officials gave him an up-close look at Russia’s strategic bombers and other warplanes.

All the Russian warplanes shown to Kim on Saturday were among the types that have seen active use in the war in Ukraine, including the Tu-160, Tu-95 and Tu-22 bombers that have regularly launched cruise missiles.

Shoigu and Lt. Gen. Sergei Kobylash, the commander of the Russian long-range bomber force, explained to Kim that the Tu-160 had recently received new cruise missiles with a range of more than 6,500 kilometers (over 4,040 miles). Pointing at the weapons bay, Shoigu said that each bomber carries 12 missiles.

Russian officials have previously said that the new missile was under development, and the latest comments confirmed its deployment for the first time.

Shoigu, who had met Kim during a rare visit to North Korea in July, also showed Kim another of Russia’s latest missiles, the hypersonic Kinzhal, carried by the MiG-31 fighter jet, that saw its first combat during the war in Ukraine, according to Russia’s Defense Ministry.

Kim and Shoigu later traveled to Vladivostok, where they inspected the Admiral Shaposhnikov frigate. Russia’s navy commander, Adm. Nikolai Yevmenov, briefed Kim on the ship’s capabilities and weapons, which include long-range Kalibr cruise missiles that Russian warships have regularly fired at targets in Ukraine.

Kim’s visits to military and technology sites this week possibly hint at what he wants from Russia, perhaps in exchange for supplying munitions to refill Putin’s declining reserves as his invasion of Ukraine becomes a drawn-out war of attrition.

Kim’s trip to Russia, which included more than four hours of talks with Putin on Wednesday, comes amid momentum in military cooperation between the countries in which North Korea could potentially seek Russian technologies to advance Kim’s nuclear, missile and other military programs in exchange for providing Russia with badly needed munitions.

Videos released by Russia’s Defense Ministry showed Shoigu greeting Kim at the airport along with honor guards lined up near a red carpet. Kim was seen peering at the Kinzhal missile, gesturing and asking questions about the warplanes’ capabilities as he discussed technical details with Shoigu and other military officials through translators.

Kim was also seen talking to Shoigu and Yevmenov about a purported nuclear attack submarine the North unveiled last week as they stepped out of the Shaposhnikov frigate.

The visit follows Kim’s tour on Friday of a factory producing advanced Russian warplanes.

Kim in recent months has emphasized the need to strengthen his navy to counter the advanced naval assets of the United States, which has been expanding its combined military exercises with South Korea to counter the North’s growing threat.

Analysts say Kim’s focus on naval strength could be driven by ambitions to obtain sophisticated technologies for ballistic missile submarines and nuclear-propelled submarines as well as to initiate joint naval exercises between Russia and North Korea.

After meeting Putin at Russia’s main spaceport, a location that pointed to Kim’s desire for Russian assistance in his efforts to acquire space-based reconnaissance assets and missile technologies, North Korea’s leader reappeared Friday in the far eastern city of Komsomolsk-on-Amur for a visit to a plant producing Russia’s Su-57 fighter jets.

Experts have said potential military cooperation between the countries could include efforts to modernize North Korea’s outdated air force, which relies on warplanes sent from the Soviet Union in the 1980s.

Kim’s trip to Russia, his first since April 2019 when he met Putin in Vladivostok, came days after he attended a ceremony at a North Korean military shipyard where the country unveiled the alleged nuclear attack submarine.

State media claimed it is capable of launching tactical nuclear weapons from underwater. But South Korea’s military expressed doubt about the operational capabilities of the sub, which was the result of reshaping an existing submarine to install missile launch tubes.

Kim has also announced goals to acquire nuclear-propelled submarines, which can quietly travel long distances and approach enemy shores to deliver strikes, a key asset in his efforts to build a viable nuclear arsenal that could threaten the United States. Analysts say such capacities would be unfeasible for the North without external assistance.

Putin on Friday reiterated that Russia would abide by U.N. sanctions, some of which ban North Korea from exporting or importing any weapons. Kremlin spokesperson Dmitry Peskov separately said that no agreements on bilateral military cooperation were signed after the Putin-Kim meeting Wednesday.

Experts say North Korea and Russia aren’t likely to publicize any deals on weapons to avoid stronger international criticism.

Kim, whose visit to Russia is his first foreign trip since the COVID-19 pandemic, has been eager to boost the visibility of his partnerships with Moscow and Beijing as he attempts to break out of international isolation and insert Pyongyang in a united front against Washington. Some South Korean experts say that Kim could also pursue a meeting with Chinese President Xi Jinping.

In another sign of the North’s post-pandemic opening, KCNA said Saturday that a team of North Korean athletes departed from Pyongyang to participate in the Asian Games starting next week in Hangzhou, China. South Korea’s government says around 190 North Korean athletes are registered for the event.

Since last year, the U.S. has accused North Korea of providing ammunition, artillery shells and rockets to Russia, many of them likely copies of Soviet-era munitions. South Korean officials said North Korean weapons provided to Russia have already been used in Ukraine.