Joe Biden's decision to approve the use of US-supplied longer-range missiles by Ukraine to strike inside Russia will "add fuel to the fire" in the conflict, a Kremlin spokesman has said.
Dmitry Peskov repeated earlier warnings from Vladimir Putin, saying that any strikes on Russian soil using US weapons would be interpreted as direct Nato involvement.
Mr Peskov said Russia was only aware of the apparent decision by the Biden administration from reporting in Western media.
He said: "It is obvious that the outgoing administration in Washington intends to take steps and they have been talking about this, to continue adding fuel to the fire and provoking further escalation of tensions around this conflict."
