Russia has been telling the West for months how it would interpret such a decision, and that it would raise the risk of a confrontation with the US-led NATO alliance.
When asked about reports by the New York Times and Reuters that Biden's administration had made the decision on long-range strikes, Kremlin spokesman Dmitry Peskov noted the reports were not based on any official statement.
President Vladimir Putin's regime has been warning the West for months about such a decision. (AP PHOTO)
"If such a decision was indeed formulated and brought to the Kyiv regime, then this is a qualitatively new round of tension and a qualitatively new situation from the point of view of US involvement in this conflict," Peskov said on Monday.
President Vladimir Putin made Russia's position absolutely clear when speaking in St Petersburg in September, Peskov said.
Putin said on September 12 that Western approval for such a step would mean "the direct involvement of NATO countries, the United States and European countries in the war in Ukraine" because NATO military infrastructure and personnel would have to be involved in the targeting and firing of the missiles.
"It is obvious that the outgoing administration in Washington intends to take steps to continue adding fuel to the fire and continue to provoke tension around this conflict," Peskov said.
Reuters reported the Biden administration's decision on Sunday, citing two US officials and a source familiar with the decision.
The US made the decision to help Ukraine resist North Korea and Russian forces in Kursk. (AP PHOTO)
The New York Times also reported the decision.
Sources quoted in both reports presented the move as partly in response to the reported arrival of North Korean soldiers in Russia's Kursk region to help repel a Ukrainian incursion.
The move comes two months before president-elect Donald Trump takes office on January 20 and follows months of pleas by Ukrainian President Volodymyr Zelenskiy to allow Ukraine's military to use US weapons to hit Russian military targets far from its border.
One Russian official close to the Kremlin who spoke on condition of anonymity said the US move, if confirmed, was an extremely provocative one for an outgoing administration but would not change the outcome of the war.
Ukraine's seizure of a piece of the Kursk region this year marked the first time US weapons had been used on internationally recognised sovereign Russian soil since Russia sent troops into Ukraine in early 2022.
"Biden's administration is trying to escalate the situation to the maximum while they still have power and are still in office," Russian MP Maria Butina said.
Ukrainian President Volodymyr Zelenskiy has long sought permission to use US long-range weapons. (AP PHOTO)
"I have a great hope that (Donald) Trump will overcome this decision if this has been made because they are seriously risking the start of World War III, which is not in anybody's interest."
Russian officials have repeatedly cautioned that the West is playing with fire by probing the limits of what a nuclear power might or might not tolerate.
Putin has changed Russia's nuclear doctrine to say that any conventional attack on Russia aided by a nuclear power could be considered to be a joint attack on Russia.
In late October, Putin said his defence ministry was working on different ways to respond if the United States and its NATO allies helped Ukraine to strike deep into Russia with long-range Western missiles.
"I guess there are some people in the United States who have nothing to lose for whatever reason, or who are completely off the grid so much that they simply do not care," said Butina, who spent 15 months in a US prison for acting as an unregistered Russian agent and is now a MP for the ruling United Russia party.
