Kremlin spokesman Dmitry Peskov was speaking a day after President Vladimir Putin said Moscow had fired the new missile - the Oreshnik or Hazel Tree - at a Ukrainian military facility in response to Kyiv striking Russia with US-made and British-made missiles this week for the first time after the US granted its approval.
"The main message is that the reckless decisions and actions of Western countries that produce missiles, supply them to Ukraine, and subsequently participate in strikes on Russian territory cannot remain without a reaction from the Russian side," Peskov told reporters.
"The Russian side has clearly demonstrated its capabilities, and the contours of further retaliatory actions in the event that our concerns are not taken into account have been quite clearly outlined," he said.
Peskov said Russia had not been technically obliged to warn the United States about the strike because the missile used had been intermediate-range rather than intercontinental, but he said Moscow had informed the US 30 minutes before the launch anyway.
He said Putin remained open to dialogue, but that the outgoing administration of US President Joe Biden "prefers to continue down the path of escalation" and urged it to heed a warning Putin issued in September.
SD/