KYIV -- The Russian Armed Forces have attacked multiple locations since Russian President Vladimir Putin authorized on Thursday morning "a special military operation" in Donbass.

Moscow expressed its willingness to talk with Kyiv with a focus on obtaining a guarantee of neutral status and non-deployment of offensive weapons in Ukraine. Here is a timeline of some major events related to the current crisis:

Feb 25, 2022

-- A total of 137 Ukrainian soldiers were killed and another 316 injured on the first day of the conflict, Ukrainian President Volodymyr Zelensky said in a video message on Thursday night.

Feb 24, 2022

-- US President Joe Biden announced on Thursday additional sanctions against Russia and the deployment of more troops to Europe as conflicts in Ukraine continue to evolve.

-- Advisor to head of the President's Office of Ukraine Mykhailo Podoliak said Russian forces seized Chernobyl nuclear power plant, the Interfax-Ukraine news agency reported.

"After a fierce battle, our control over the Chernobyl site has been lost," Podoliak said.

-- The Russian Defense Ministry said that a total of 11 airfields, three command posts, a Ukrainian naval base, and 18 radar stations of the S-300 and Buk-M1 air defense missile systems were among the facilities destroyed.

-- Kremlin spokesman Dmitry Peskov said that Putin has expressed his preparedness to engage in discussions with his Ukrainian counterpart with a focus on obtaining a guarantee of neutral status and non-deployment of offensive weapons in Ukraine.

-- Ukraine on Thursday severed diplomatic relations with Russia. Ukrainian President Volodymyr Zelensky declared martial law in the country following Russia's military operation.

-- According to the Russian Defense Ministry, the Russian Armed Forces are destroying "military infrastructure, air defense facilities, military airfields, aviation of the Ukrainian Armed Forces" with high-precision weapons, not targeting Ukrainian cities.

-- Putin on Thursday authorized "a special military operation" in Donbass.

"Our plans do not include the occupation of Ukrainian territories. We are not going to impose anything on anyone by force," Putin said in a televised speech to the nation, noting that Russia's move is in response to "fundamental threats" of the North Atlantic Treaty Organization which has expanded to eastern Europe and brought its military infrastructure closer to Russian borders.

-- According to the Russian Defense Ministry, the Russian Armed Forces are destroying "military infrastructure, air defense facilities, military airfields, aviation of the Ukrainian Armed Forces" with high-precision weapons, not targeting Ukrainian cities.

-- Ukraine on Thursday severed diplomatic relations with Russia. Ukrainian President Volodymyr Zelensky declared martial law in the country following Russia's military operation.

Feb 21, 2022

-- The Russian Security Council held an extraordinary meeting, when the country's top officials supported the recognition of Lugansk and Donbass.

-- Putin signed two decrees recognizing Lugansk and Donbass as independent and sovereign states.

At a ceremony held in the Kremlin, Putin also inked the Treaty of Friendship, Cooperation and Mutual Assistance between Russia and Lugansk and Donbass respectively.

-- Through a statement attributable to his spokesperson, UN Secretary-General Antonio Guterres called for "peaceful settlement" of the conflict in eastern Ukraine, in accordance with the Minsk Agreements, as endorsed by the Security Council in resolution 2202 (2015).

-- At the Security Council emergency meeting on Ukraine, China's permanent representative to the United Nations, Zhang Jun, called on all parties concerned to seek "reasonable solutions" to the Ukraine issue.

Feb 18, 2022

-- An explosion occurred close to "DPR government building." Local armed groups in eastern Ukraine ordered the evacuation of civilians to Russia, citing the danger of a possible military offensive.

Feb 17, 2022

-- The Ukrainian military claimed that local armed groups in eastern Ukraine launched shelling on the area controlled by government forces. Local armed groups in eastern Ukraine accused the Ukrainian government forces of first using heavy weapons to attack areas under their control. Tensions in eastern Ukraine continued to escalate.

Feb 2, 2022

-- The United States decided to deploy additional troops to Europe, including 1,000 troops to be repositioned to Romania and another 2,000 troops to be sent from the United States to Germany and Poland, in preparation for what it claimed to be an "imminent" Russian invasion of Ukraine.

Jan 26, 2022

-- US Secretary of State Antony Blinken announced that the United States has delivered a written letter to Russia addressing Moscow's concerns amid escalating tensions on Ukraine's border.

Jan 22, 2022

-- The Ukrainian Defense Ministry said the first shipment of military aid from the United States arrived in Kyiv.

Jan 10-13, 2022

-- The latest round of talks aimed at defusing tensions between Russia and the West within the framework of the Organization for Security and Cooperation in Europe ended without a breakthrough as both sides warned of potential escalation.

Dec 10, 2021

-- The Russian Foreign Ministry demanded "legal guarantees" that NATO wouldn't expand eastward.

Feb 7, 2019

-- The Ukrainian parliament passed a constitutional amendment stating Ukraine's commitment to joining NATO.

Feb 12, 2015

-- The leaders of Ukraine, Russia, Germany and France announced a peace deal in the Belarusian capital of Minsk, which envisaged a ceasefire between Ukrainian government troops and local armed groups in eastern Ukraine.

Dec 23, 2014

-- The Ukrainian parliament renounced Ukraine's "non-aligned" status with the aim of deepening cooperation with NATO.

Sept 5, 2014

-- Then Ukrainian President Petro Poroshenko and local armed groups in eastern Ukraine signed a ceasefire protocol in Minsk, where envoys from the two warring sides as well as Russia and the Organization for Security and Cooperation in Europe held talks for a possible political solution to the crisis.

April 2014

-- Unrest erupted in eastern Ukraine, where protesters seized government buildings, demanding a referendum on autonomy and closer ties with Russia.

February 2014

-- Amid rising protests, Ukraine's parliament voted to dismiss then President Viktor Yanukovych and set early elections.

November 2013

-- The Ukrainian government suspended the signing of partnership agreements with the European Union to avoid straining ties with Russia, triggering widespread protests, which soon snowballed into a violent nationwide movement against the authorities.