Moscow has warned that retaliatory actions are being prepared after accusing Ukraine of launching another round of ATACMS strikes into Russian territory.
Russian military on Tuesday pledged a response to the fresh air attacks using the US-supplied missiles, which Russias defence ministry said were carried out on November 23 and 25.
Retaliatory actions are being prepared, it said in a post on Telegram, without providing any further details.
In a rare admission, Russia said the fresh strikes had caused damage to military hardware and wounded some of its personnel on the ground.
A strike on the Kursk Vostochny air base wounded two servicemen, the defence ministry said, while a strike on an air defence battery damaged a radar system and also caused casualties.
It said three of the five missiles fired in the first strike were shot down, while seven of the eight used in the second were destroyed.
Moscow rarely provides such specific details on Ukrainian aerial attacks and almost never admits missiles have reached their intended target.
The defence ministry also posted photos of what it said were the missile fragments, showing large casings with English-language inscriptions on the side.
Remains of US-produced ATACMS missiles, fired by Ukrainian armed forces on November 25, according Russias defence ministry, are seen at the Kursk-Vostochny airport (Khalino) in the Kursk region, Russia, on November 26
Russias defence ministry said three of the five missiles fired in the first strike were shot down, while seven of the eight used in the second were destroyed
US Army Tactical Missile System (ATACMS) is seen in action
The United States gave Ukraine permission to use the weapons to hit Russian territory just over a week ago, after months of requests from Kyiv.
The latest attacks come after war-torn country launched its first strike on Russian territory using the US-supplied long-range missiles last week.
An explosion at an ammunition depot in Karachev around 75 miles from the Ukrainian border in Russias Bryansk region lit up the night sky in the early hours of Tuesday morning on what was the 1,000th day of the war.
The reports emerged within minutes of the Kremlin threatening a nuclear response should Ukraine hit targets on Russian soil with Western-supplied long-range munitions.
The Russian Federation reserves the right to use nuclear weapons in the event of aggression against it with the use of conventional weapons, Kremlin press secretary Dmitry Peskov told reporters in Russia this morning.
His statement followed Vladimir Putins approval of an updated nuclear doctrine that allows his strategic forces to deploy nuclear weapons if Russian or Belarusian territory is threatened by a non-nuclear nation supported by a nuclear power.
Threats that could make Russias leadership consider a nuclear strike include an attack with conventional missiles, drones or other aircraft, according to the updated document.
A Ukrainian strike on Russian territory with US-supplied missiles meets these criteria, raising fears that Moscow may now consider a dramatic escalation in the conflict.
The strike carried out by Ukraineon November 20 was the first time UK Storm Shadow missiles had been used blast targets deep inside Russia. One image following the attack showed a written indentation on a chunk of metal reading: Storm Shadow
Now, as fears grow over the potential fallout of Western missiles striking targets in Russia, Ukrainian President Volodymyr Zelensky is insisting that 2025 will prove a decisive year in determining who wins the war.
In the decisive moments - and they are coming next year - we must not allow anyone in the world to doubt the resilience of our entire state, the Ukrainian president told Parliament in a rousing address today.
At this stage, it is being decided who will prevail.
On November 20, Ukraine then used British-supplied Storm Shadow missiles in Russia for the first time when 12 rockets were fired at targets in Kursk – the southern Russian province where Kyiv troops have seized territory.
The attacks were reportedly personally approved by UK PM, Sir Keir Starmer.
The rockets destroyed a building with an underground control room where Russian and North Korean military officials were believed to be holed up, according to Ukrainian defence experts.
Britain conceded permission to use the Storm Shadow missiles against attacks within Ukraine earlier this year.
The missiles will allow Ukraine to take out military targets and airbases previously unreachable, capable of hitting hard into Ukraine.
Storm Shadows are capable of dodging air defences - making them a nightmare attack weapon for their enemy.
This is the moment missiles believed to be British Storm Shadow missiles struck inside Russia
Britains Storm Shadow missiles are capable of dodging air defences - making them a nightmare attack weapon for their enemy
The £800,000 rockets use GPS technology to precisely blast targets, and can travel through the air at 600mph.
When quizzed on letting Ukraine use the UK-made missiles, the PM last week said: Ive been doubling down in my clear message that we need to ensure Ukraine has what is needed for as long as needed to win this war against Putin.
I am not going to go into operational details. You would not expect me to. The only winner in that would be Putin and it would undermine Ukraine.
The single simplest way to end this conflict is for Russia to stop the aggression and to stop it today. We are on day 1,000 of that aggression.
Russia then responded to the strikes by launching Putins hypersonic Oreshnik missile at Ukraine on November 21.
The debris from the medium-range ballistic missile that was fired at the city of Dnipro on Thursday is now being studied by Ukrainian investigators as it historically became the first time such a powerful weapon has been used in the war.
Ukraine said the weapon reached a top speed of more than 8,000mph as it headed towards Dnipro.
Zelensky called the use of the weapon, which is capable of carrying multiple nuclear warheads, a severe escalation and urged his allies to respond.
Following the series of air attacks, there are growing concerns around the potential beginnings of World War Three.
The moment Russia used the Oreshnik for the first time to strike Dnipro, on November 21
A view shows a site of a Russian missile strike, amid Russias attack on Ukraine, in Dnipro
Russia on November 21 fired an experimental missile at Ukraine, officials from Western governments said. Ukraine initially accused Russia of firing in an attack on Dnipro an intercontinental ballistic missile (ICBM) in combat for the first time in history
Fragments of a rocket which struck Dnipro on November 21 are seen at a center for forensic analysis in an undisclosed location in Ukraine, November 24
Russian T90M tank firing towards Ukrainian positions, at an undisclosed location in Russia
Ukraines former military chief on Friday warned that WW3 is already underway - with Vladimir Putins autocratic allies, North Korea, Iran and China, openly supporting his forces on the battlefield.
Valery Zaluzhny, who is now Ukraines envoy to the United Kingdom, told the UP100 award ceremony in Kyiv: I believe that in 2024 we can absolutely believe that the Third World War has begun.
The General said that as of this year, Ukraine is no longer facing Russia. Soldiers from North Korea are standing in front of Ukraine.
He made the comments after reports emerged that around 10,000 soldiers had been sent by Pyongyang to fight alongside Russian troops in the Kursk region, as Moscow aims to replenish its forces and reclaim the territory taken from it three months ago.
It comes after Moscows ambassador to the UK declared that Britain is now directly involved in the war after Kyivs Storm Shadow attack on Russian territory.
Asked if the UK is at war, the Starmer told BBC local radio: Were not at war, but Ukraine certainly is. Sir Keir slammed Putins irresponsible rhetoric.
Russia is the aggressor, he said. This war could end today if Putin stopped being the aggressor.