Western security analysts say Putin's statements are designed to deter and intimidate, but they have not prevented the United States and its NATO allies from providing aid, intelligence, training and weapons to Ukraine - including tanks and long-range missiles - in ways that were unthinkable at the start of the war.

Feb. 24, 2022 - Putin says in a speech to launch his "special military operation" in Ukraine that Russia is a leading nuclear power "and possesses certain advantages in some of the newest types of weaponry. In this regard, no one should have any doubts that a direct attack on our country will lead to defeat and horrible consequences for any potential aggressor."

He later adds: "Whoever tries to hinder us, or threaten our country or our people, should know that Russia’s response will be immediate and will lead you to consequences that you have never faced in your history."

Feb. 27, 2022 - Putin says he has ordered Russia's nuclear forces onto high alert.

Sept. 21, 2022 - Putin orders Russia's first military mobilisation since World War Two and says: "If the territorial integrity of our country is threatened, we will without doubt use all available means to protect Russia and our people - this is not a bluff."

Sept. 30, 2022 - Putin says the United States created a "precedent" when it dropped two atomic bombs on Japan in 1945.

Dec. 9, 2022 - Putin says any country that dared to attack Russia with nuclear weapons would be wiped from the face of the earth. He says Russia has no mandate to launch a preventative first nuclear strike but that Russia's advanced hypersonic weapons would ensure Russia could respond forcefully if it ever came under attack.

Feb. 22, 2023 - Putin says Russia will suspend its participation in the New START treaty with the United States that limits the number of nuclear warheads each side can deploy.

He says Russia must be ready to conduct a nuclear test in case the United States does so.

March 25, 2023 - Putin says Russia has struck a deal with its ally Belarus, which borders Ukraine, to station tactical nuclear weapons on its territory. He says this mirrors deployments that the United States has made for decades in allied countries in Europe.

Oct. 5, 2023 - Putin says he sees no need to change Russian doctrine which says it may use nuclear weapons in the event of a nuclear attack or a conventional threat to the existence of the state. He says any attack on Russia would provoke a split-second response with hundreds of nuclear missiles that no enemy could survive. "I think no person of sound mind and clear memory would think of using nuclear weapons against Russia."

Putin says Russia has tested and will soon place on combat duty its latest nuclear-capable weapons, the Burevestnik cruise missile and Sarmat intercontinental ballistic missile. He says parliament should review Russia's position on the Comprehensive Test Ban Treaty to "mirror" the position of the United States, which has not ratified it. Within weeks, parliament withdraws Russia's ratification of the treaty.

Feb. 22, 2024 - Putin sends a signal to the West by taking a short flight on a modernised Tu-160M nuclear-capable strategic bomber plane.

Feb. 29, 2024 - Putin tells Western countries they risk provoking a nuclear war if they send troops to fight in Ukraine. He says they "must realise that we also have weapons that can hit targets on their territory. All this really threatens a conflict with the use of nuclear weapons and the destruction of civilisation. Don't they get that?"

March 13, 2024 - Asked in an interview if Russia is really ready for a nuclear war, Putin says: "From a military-technical point of view, we are, of course, ready." He says, however, that he sees no rush towards nuclear confrontation and that Russia has never faced a need to use nuclear weapons in Ukraine.