Moscow: The Kremlin on Thursday declined to comment when asked if Russia was helping North Korea to develop its missile and other military technology following a test launch by Pyongyang of an intercontinental ballistic missile.
North Korea said it had tested the missile on Thursday, upgrading what it called the "world's most powerful strategic weapon", as Seoul warned Pyongyang could get missile technology from Russia for helping with the war in Ukraine.
The United States and NATO say some North Korean soldiers are in the Kursk region, a Russian border area which Ukrainian forces punched their way into in August and where they continue to hold territory. A couple of thousand more North Korean troops were heading there, the Pentagon said on Tuesday.
Moscow has neither denied nor directly confirmed the presence of North Korean troops on its soil, with President Vladimir Putin saying it is Russia's business whether or not it decides to use North Korean troops.
When asked on a conference call on Thursday whether Moscow was helping North Korea with missile or other military technology, Kremlin spokesman Dmitry Peskov told reporters: "I do not have that information, it is specialised information and you should ask the Ministry of Defence."
Peskov referred to the importance of a comprehensive strategic partnership, which included a mutual defence clause, that was signed by Putin and North Korean leader Kim Jong Un during a visit to Pyongyang by the Russian leader in June.
"Once again, I can only repeat that we remain committed to the treaty that we signed, we remain committed to our interests to develop relations with our neighbour in all areas, and this should not worry and concern anyone," said Peskov.
"It is the sovereign right of Russia and the DPRK (Democratic People's Republic of Korea) to develop relations as neighbouring states."
Russia said on Wednesday that North Korean Foreign Minister Choe Son Hui was on her way to Moscow to hold strategic consultations with her Russian counterpart Sergei Lavrov, her second visit to Russia in six weeks.