Russian president Vladimir Putin has agreed to travel to North Korea on the invitation of leader Kim Jong-un for more talks on their “far-reaching plan” for a deeper partnership, state media reported. Increasingly isolated from the rest of the world, the two leaders held a summit on Wednesday in Russia’s far east where they agreed to help prop up each other’s regime. Mr Putin offered to support North Korea’s UN-sanctioned satellite launch programme, while Mr Kim suggested Russia had Pyongyang’s full backing in its “sacred” invasion of neighbour Ukraine. Mr Kim is continuing his visit to Russia, where he is scheduled to tour various defence equipment manufacturing facilities and view a display of Russian warships. His trip will end with a stop at a marine biology facility – or so it was described by Mr Putin – in the eastern city of Vladivostok, before he returns with his armoured train to North Korea. No timeline for their next meeting has been set, with Mr Putin accepting the invititation to travel to North Korea at “a convenient time”, according to state media. The two leaders exchanged gifts at the beginning of their meeting on Wednesday, according to North Korea’s KCNA news agency, and the North Korean leader – said to be a car enthusiast – had a go in Mr Putin’s Russian-made limousine. "At the end of the reception, Kim Jong-un courteously invited Putin to visit the DPRK at a convenient time," KCNA said, referring to the Democratic People’s Republic of Korea, North Korea’s official name. "Putin accepted the invitation with pleasure and reaffirmed his will to invariably carry forward the history and tradition of the Russia-DPRK friendship," it said. Mr Kim said their bilateral ties have reached a new level with their meeting, and expressed his willingness to foster stable, future-oriented relations for the next 100 years. The two leaders, both facing crippling sanctions from the international community, met for talks running over four hours as Mr Putin is believed to be seeking a deal for weapons and munitions, an area where North Korea has excelled, to feed his war machine in Ukraine. The possibility of Russia’s arms deal with North Korea has sparked concerns, with the US State Department saying that they “will not hesitate” to impose additional sanctions on Moscow and Pyongyang. It was "troubling" that Russia is discussing cooperation with North Korea on programs that would violate UN Security Council sanctions, State Department spokesperson Matthew Miller said after the summit. During a dinner hosted by Mr Putin for his North Korean counterpart, the two leaders praised each other and celebrated the 75 years of diplomatic relations between their countries. Mr Putin reminded Mr Kim of the cooperation between Soviet and Korean soldiers during the Korean War. Mr Kim said that the two leaders have come to “a satisfactory consensus” for further strengthening their strategic and tactical cooperation in their battle to secure guarantees for a lasting peace in the region and the world, according to the Kremlin. “We are confident that the Russian army and people will inevitably attain victory in the sacred struggle to punish the evil crowd, which claims the right to hegemony based on the illusion of expansionism, a struggle to create the stability needed for development,” Mr Kim added. Neighbouring South Korea expressed deep concerns over North Korea’s military cooperation and possible arms transactions between Pyongyang and Moscow South Korea‘s unification minister, Kim Young-ho, said the two countries were apparently continuing to pursue “some kind of” a military deal. “We once again urge Russia and North Korea to halt illicit acts that cause their isolation and regression, and follow international rules including the Security Council resolutions,” the minister told reporters. Russia is preparing for a longer war in Ukraine and it is unable to meet the necessary industrial capacity, said James Nixey, director of the Russia and Eurasia program at Chatham House, a London-based think-tank. In return, Pyongyang is likely seeking to get food and missile technology from Moscow, “a relatively easy gift” for the Kremlin, Mr Nixey said. James O’Brien, head of the Office of Sanctions Coordination at the US State Department, said Russia was “scraping the bottom of the barrel looking for help because it’s having trouble sustaining its military”. A deal between the countries would violate existing sanctions, Mr O’Brien said, and would trigger the US to try to identify the individuals and the financial mechanisms used to “at least limit their ability to be effective”. Additional reporting by agencies Read More Isolated Putin and Kim posture over ‘sacred fight’ with West as they talk arms for Moscow’s war machine Weapons, spy satellites and nuclear ambitions: what we learned from Putin’s summit with Kim Jong-un in Russia Putin’s meeting with Kim is sign of Kremlin’s isolation, claims No 10 The Body in the Woods | An Independent TV Original Documentary The harrowing discovery at centre of The Independent’s new documentary