President Vladimir Putin warned of an escalation towards a "global" conflict after the U.S. and Britain allowed Ukraine to hit Russia with their weapons, adding they could retaliate by hitting "countries that allow their weapons to be used against our facilities."
Putin said Russia had responded to the use of U.S. and British missiles by firing a new kind of hypersonic medium-range ballistic missile at a Ukrainian military facility.
After approval from the administration of President Joe Biden, Ukraine struck Russia with six U.S.-made ATACMS on November 19 and with British Storm Shadow missiles and U.S.-made HIMARS two days later, Putin added.
"From that moment, as we have repeatedly underscored, a regional conflict in Ukraine previously provoked by the West has acquired elements of a global character," Putin said in an address.
"In case of escalation of aggressive actions, we will also respond decisively and in a mirror manner."
Putin said the Ukrainian missile attack with ATACMS had failed to inflict any serious damage, but the Storm Shadow attack on Kursk region on November 21 had been directed at a command point and led to deaths and injuries.
"The use by the enemy of such weapons is not able to change the course of the military actions in the zone of the special military operation," Putin said.
"We consider ourselves entitled to use our weapons against the military facilities of those countries that allow their weapons to be used against our facilities. If anyone else doubts this, then they are wrong - there will always be a response."
Putin said Moscow had tested a new medium-range hypersonic non-nuclear ballistic known as "Oreshnik" (the hazel) by firing it at a missile and defense enterprise in the Ukrainian city of Dnipro, where missile and space rocket company Pivdenmash, known as Yuzhmash by Russians, is based.
Russia, he added, was developing short and medium range missiles in response to the planned production and then deployment by the U.S. of medium and shorter range missiles in Europe and the far east.
"I believe the United States made a mistake by unilaterally destroying the treaty on the elimination of intermediate-range and shorter-range missiles in 2019 under a far-fetched pretext," Putin said, referring to the Intermediate-Range Nuclear Forces (INF) Treaty.
The U.S. formally withdrew from the landmark 1987 (INF) Treaty with Russia in 2019 after saying Moscow was violating the accord, an accusation the Kremlin denied.
Zelenskyy responds
Ukraine's President Volodymyr Zelenskyy branded the strike a major ramping up of the "scale and brutality" of the conflict by a "crazy neighbor", while the US. said Russia was to blame for escalating the conflict "at every turn".
Criticising the global response to the strike - "final proof that Russia definitely does not want peace" - Zelenskyy warned other countries could become targets for Putin too.
"It is necessary to urge Russia to a true peace, which is possible only through force," the Ukrainian leader said. "Otherwise, there will be relentless Russian strikes, threats and destabilization, and not only against Ukraine."
The attack on Dnipro comes just days after several foreign embassies shuttered temporarily in the Ukrainian capital, citing the threat of a large-scale strike.
The spokesman for UN Secretary-General Antonio Guterres, Stephane Dujarric, said the new missile's deployment was "another concerning and worrying development," warning the conflict was "going in the wrong direction."