Lavrov arrived Wednesday night for a two-day visit after accompanying President Vladimir Putin on a trip to Beijing.

The veteran envoy's meetings in Pyongyang are expected to lay the groundwork for a future visit by Putin, who was invited by North Korean leader Kim Jong Un last month at a high-profile summit in Russia's far east.

"After the landmark summit ... we can say confidently that (Russia-North Korea) relations have reached a qualitatively new, strategic level," Lavrov reportedly told North Korean Foreign Minister Choe Son Hui at a Thursday meeting.

The night before he touted North Korea's support for Russia's ongoing war in Ukraine after his arrival in Pyongyang.

"We highly value your principled, unambiguous support for Russia's actions in connection with the special military operation in Ukraine," Lavrov was quoted as saying by Russia's RIA news agency.

Kim travelled to Russia last month aboard a specially built bullet-proof train for a face-to-face meeting with Putin, declaring bilateral ties with Moscow his country's "number one priority".

The September meeting fanned Western fears Pyongyang might provide Moscow with weapons for its drawn-out war in Ukraine.

On Friday, the United States said arms shipments were already under way, with North Korea delivering more than 1,000 containers of military equipment and munitions to Russia in recent weeks.

Pyongyang was seeking a range of military assistance in return, including advanced technologies, White House national security spokesman John Kirby told reporters.

Moscow this week denounced the allegations, insisting Washington has no proof that weapons are being shipped.