In 1994, Ukraine agreed to accede to the Treaty on the Non-Proliferation of Nuclear Weapons as a non-nuclear-weapon state.
In November, Prime Minister Viktor Yanukovych was declared the winner, despite allegations of vote-rigging by election observers.During a two-month period which became known as the Orange Revolution, large peaceful protests successfully challenged the outcome.
On February 12, 2008, then Russian President Vladimir Putin said Russia may target its missiles at Ukraine if its neighbour joins NATO and accepts the deployment of a US missile defence shield.Russia
Ukrainian president Zelenskyy declared that 16 February, a speculated date for the invasion, would be a "Day of Unity".
In a 21 February speech, Putin questioned the legitimacy of the Ukrainian state, repeating an inaccurate claim that "Ukraine never had a tradition of genuine statehood".
In October 2021, A greater numbers of soldiers and with deployments on new fronts; by December over 100,000 Russian troops were massed around Ukraine on three sides.
On 30 November 2021, Russian President Putin stated that an expansion of NATO's presence in Ukraine, especially the deployment of any long-range missiles capable of striking Russian cities or missile defense systems similar to those in Romania and Poland, would be a "red line" issue for Russia.
On December 1, 2021, Russian President Vladimir Putin said he wanted to receive guarantees from the West that Ukraine would not join NATO.
On 18 February, the Donetsk and Luhansk people's republics ordered all civilians to leave their capitals, although observers noted that full evacuations would take months.
On 21 February, the head of the Russian Federal Security Service (FSB) said that Russian forces had killed five Ukrainian "saboteurs" that crossed into Russian territory, capturing one Ukrainian serviceman and destroying two armoured vehicles.
On 21 February, Putin announced that the Russian government would recognise the Donetsk and Luhansk people's republics.
On 21 February 2022, Russia officially recognized the two breakaway regions in eastern Ukraine, the Donetsk People's Republic and the Luhansk People's Republic, as independent states, and deployed troops to Donbas, in a move interpreted as Russia's effective withdrawal from the Minsk Protocol.
On 22 February, video footages shot in the early morning shown Russian armed forces and tanks moving in the Donbas region.
Shortly before 06:00 Moscow Time (UTC+3) on 24 February, Putin announced that he had made the decision to launch a "special military operation" in eastern Ukraine. Russian troops entered Ukraine from the north in Belarus (towards Kyiv); from the northeast in Russia (towards Kharkiv); from the east in the DPR and the Luhansk People's Republic; and from the south in Crimea.
Snake Island, a Ukrainian island in the Black Sea, was attacked on 24 February 2022 during the early stages of the 2022 Russian invasion of Ukraine.
The Siege of Mariupol is a military engagement between Russia and Ukraine which began on 24 February 2022, during the 2022 Russian invasion of Ukraine, as part of the Eastern Ukraine offensive.
Antonov Airport in Hostomel, Kyiv Oblast was attacked on 24 February 2022 during the 2022 Russian invasion of Ukraine due to its strategic value as a potential air bridge for Russian troops. The attack intensified into a battle for control of the airport in which fighting continued until the next day, resulting in a Russian victory.
Russian forces were invading via land near the city of Kharkiv and large-scale amphibious landings were reported in the city of Mariupol.
Snake Island, a Ukrainian island in the Black Sea, was attacked on 24 February 2022 during the early stages of the 2022 Russian invasion of Ukraine.
The Battle of Okhtyrka is a military engagement, which began on 24 February 2022, during the 2022 Russian invasion of Ukraine, as part of the Northeastern Ukraine offensive, in the city of Okhtyrka, which is dubbed the oil capital of Ukraine, located near the Russia-Ukraine border.
On 24 February 2022, the Chuhuiv Air Base in Chuhuiv, Kharkiv Oblast, Ukraine was the target of an air strike by Russian forces as part of the Northeastern Ukraine offensive during the 2022 Russian invasion of Ukraine.
The Battle of Konotop was a military engagement that took place around the city of Konotop, Ukraine between the military forces of Russia and Ukraine as part of the Northeastern Ukraine offensive during the 2022 Russian invasion of Ukraine.
At 22:35 (UTC+3), Russian President Vladimir Putin announced that Russia recognizes the independence of two pro-Russian breakaway regions in eastern Ukraine.
The Battle of Kyiv is a military battle that began on 25 February 2022, as part of the Kyiv offensive in the 2022 Russian invasion of Ukraine for control of Kyiv, the capital city of Ukraine.
The Battle of Volnovakha was a military engagement which lasted from 25 February 2022 until 12 March 2022, as part of the Eastern Ukraine offensive during the 2022 Russian invasion of Ukraine.
After the 25 February UN Security Council meeting, Stoltenberg announced that parts of the NATO Response Force would be deployed, for the first time ever, to NATO members along the eastern border.
On 25 February 2022, the Russian air base in Millerovo, Rostov Oblast, Russia was attacked by Ukrainian forces during the 2022 Russian invasion of Ukraine. According to some Ukrainian officials, Ukrainian military forces attacked the Millerovo air base with OTR-21 Tochka missiles, destroying Russian Air Force planes and setting the airbase on fire.
Early on 26 February, the Ukrainian military said it had repelled a Russian attack on an army base located on Peremohy Avenue, a main road in Kyiv; it also claimed to have repelled a Russian assault on the city of Mykolaiv on the Black Sea.
On 26 February 2022, Ukrainian authorities announced that the civilian search and rescue ship Sapphire was captured by the Russian navy off Snake Island.
A Russian missile later hit the regional administration building on Freedom Square during a bombardment of Kharkiv, killing at least ten civilians, and wounding 35 others.
After Russia's Defense Ministry announced that it would hit targets to stop "information attacks", missiles struck broadcasting infrastructure for the primary television and radio transmitters in Kyiv, taking TV channels off the air.
Zhyvytskyi stated that Russian forces had captured Trostianets after entering it at 01:03.
Ukrainian advisor Oleksiy Arestovych stated that the Ukrainian forces had gone on the offensive for the first time during the war, advancing towards Horlivka.
Zelenskyy also announced that the first batch of international volunteers had arrived in Ukraine to fight against Russian forces.
At Zaporizhzhia Nuclear Power Plant, a projectile hit within the plant site, causing a localised fire of a building that is not part of the reactors.
By 20 March, the four incursion fronts had formed a perimeter significantly within the entire border of Eastern Ukraine and started to extensively consolidate lines of communication and support between all four fronts within Ukraine while besieging Mariupol, Kiev, Donbas, Luhansk, and other cities.
Russia began to evacuate its embassy in Kyiv. The websites of the Ukrainian parliament and government, along with banking websites, were hit by DDoS attacks, widely attributed to Russian-backed hackers.
Around 04:00 (UTC+2) local time, Kyiv was rocked with two explosions from cruise and ballistic missiles.
The Battle of Chernobyl was a military confrontation in the Chernobyl Exclusion Zone between the Russian Armed Forces and the Ukrainian Armed Forces, starting on 24 February 2022, during the first day of the 2022 Russian invasion of Ukraine.
The Battle of Vasylkiv was a military engagement between the Russian Federation and Ukraine on 26 February 2022, during the 2022 Russian invasion of Ukraine.
Military vehicles entered Ukraine through Senkivka, at the point where Ukraine meets Belarus and Russia, at around 6:48 am local time.
The Battle of Mykolaiv is a military engagement which started on the night of 26 February 2022, as part of the Southern Ukraine offensive during the 2022 Russian invasion of Ukraine.
Ukrainian and Russian forces clashed at the village of Ivankiv, the location of a key river crossing. Russian forces captured the village on 27 February.
Poland offered to transfer all its 23 MiG-29 fighter jets to the United States for free and deliver them to Ramstein Air Base in Germany, with the United States then delivering them to Ukraine.
The Estonian government issued a statement by Prime Minister Kaja Kallas saying: "Russia's widespread aggression is a threat to the entire world and to all NATO countries, and NATO consultations on strengthening the security of the Allies must be initiated to implement additional measures for ensuring the defence of NATO Allies. The most effective response to Russia's aggression is unity."