Ukraine's deputy interior minister, Anton Gerashchenko, has reported the commencement of a Russian invasion via a statement posted to his official Facebook page.
Gunfire at the Russia and Ukraine border is underway. "There is a new geopolitical reality in the world," Gerashchenko wrote after missiles were fired at military headquarters, airports and military warehouses, near Kyiv, Kharkiv, Dnieper.
Russia has launched a military attack on Ukraine after President Vladimir Putin authorised what he called a "special military operation" to "demilitarise and denazify" the neighbouring country. President Putin vowed there will be "consequences greater than any you have faced in history" if there was any attempt to interfere in a televised address at around 2.30am GMT – as an emergency meeting of the UN Security Council was under way in New York to avert conflict, the Guardian reported.
President Putin has justified the attack by claiming that "a hostile anti-Russia is being created on our historic lands", calling on Ukrainian military to lay down weapons, according to Reuters.
Addressing the Russian people, President Putin outlined that the clashes between Ukrainian and Russian forces are "inevitable" and "only a question of time", further NATO expansion and its use of Ukraine's territory are unacceptable, which under the circumstances "demanded decisive action from Russia", asserting that Russian military operation aims to "protect people".
In response, US President Joe Biden released a statement on Twitter condemning the unprovoked attack by Russian military forces.
"President [Volodymyr] Zelenskyy reached out to me tonight and we just finished speaking," President Biden said.
"I condemned this unprovoked and unjustified attack by Russian military forces.
"I briefed him on the steps we are taking to rally international condemnation, including tonight at the UN Security Council."
President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering, according to an official White House statement. Russia alone is responsible for the death and destruction this attack will bring, the United States and its Allies and partners will respond in a united and decisive way. The world will hold Russia accountable, the White House statement firmly asserted.
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UK Prime Minister Boris Johnson swiftly affirmed his support for Ukraine on Twitter, too.
"I am appalled by the horrific events in Ukraine and I have spoken to President Zelenskyy to discuss next steps," Prime Minister Johnson said.
"President Putin has chosen a path of bloodshed and destruction by launching this unprovoked attack on Ukraine.
"The UK and our allies will respond decisively."
Ursula von der Leyen, President of The European Commission, also took to Twitter, asserting that the "Kremlin will be held accountable".
"We strongly condemn Russia's unjustified attack on Ukraine," von der Leyen said.
"In these dark hours, our thoughts are with Ukraine and the innocent women, men and children as they face this unprovoked attack and fear for their lives."
In a direct plea to Russian President Putin, United Nations Secretary-General Antonio Guterres said, "In the name of humanity bring your troops back to Russia."
Russia has carried out missile strikes on Ukraine infrastructure and on Ukrainian border guards with explosions being heard in many cities across the country.
Ukraine has now introduced martial law in the face of "full-scale invasion", according to the Guardian.