Joe Biden has allowed Ukraine to strike inside Russia with long-range US missiles, prompting dire warnings from Moscow. The Kremlin has accused Washington of adding "fuel to the fire" and trying to escalate the conflict.

A Russian lawmaker calls President Biden's decision to let Ukraine fire U.S. missiles deep into Russia a "very big step toward the beginning" of a third world war.

A representative from Russia’s State Duma warned that the United States risked a provocation to World War Three if it agreed to permit Ukraine to use weapons made in the United States that have the capabilities to strike Russia further inland.

Peskov said it is obvious that the outgoing Biden administration intends to take steps to continue adding fuel to the fire provoke tension around this conflict.

Russia has warned that the Biden administration's approval for Ukraine to use long-range US missiles (ATACMS) represents a significant escalation in the conflict. Kremlin spokesperson Dmitry Peskov called it a new stage of US involvement.

Washington is easing limits on what Ukraine can strike with U.S.-made weaponry, U.S. officials told The Associated Press on Sunday.

Kremlin says any decision to allow Ukraine to fire US missiles deep into Russia would mean the US was directly involved.