Russian Foreign Minister Sergei Lavrov on Thursday slammed US policy towards North Korea as “dangerous” during a visit to Pyongyang, while touting the “new, strategic level” of relations between Moscow and the nuclear-armed state. The veteran envoy’s two-day visit is expected to lay the groundwork for a future trip to the country by Russian President Vladimir Putin, who was invited by leader Kim Jong Un last month at a high-profile summit in Russia’s far east. “Like our North Korean friends, we are seriously worried about the intensification of military activity of the United States, Japan and South Korea in the region and by Washington’s policies … we oppose this unconstructive and dangerous line,” Lavrov told journalists, Russian news agencies reported. “We oppose this unconstructive and dangerous line,” he said, adding the US was placing “strategic infrastructure, including nuclear elements”, in the region without elaborating. In the face of a record-breaking series of weapons tests by Pyongyang this year, Seoul has moved to strengthen its security relationship with traditional ally the United States while entering a new trilateral defence arrangement that also includes Japan. Seoul and Washington have staged joint military exercises with advanced stealth jets and US strategic assets, while an American nuclear-armed submarine in July made a South Korean port call for the first time in decades. A B-52 bomber capable of carrying a nuclear payload currently sits at Cheongju Airport, about 100 kilometres south of Seoul, marking the first time one has landed in the country since at least 2000. But North Korea’s relationship with Russia has also been tightening, Lavrov said Thursday. “After the landmark summit … we can say confidently that relations have reached a qualitatively new, strategic level,” Lavrov reportedly told North Korean Foreign Minister Choe Son Hui at a meeting. Moscow is also keen to assist North Korea with its energy needs, a constant source of struggle for heavily sanctioned Pyongyang, he told Russian outlets. “There is geological exploration, there are also plans for the supply of energy resources and other goods that our friends from the DPRK need,” Lavrov said, using the acronym for North Korea’s official name.