Russia attacks Ukraine: What you need to know

Ukrainian tanks move into the city, after Russian President Vladimir Putin authorized a military operation in eastern Ukraine, in Mariupol(REUTERS)

Russia has launched an invasion of Ukraine after President Vladimir Putin ordered a "specialised military operation " in the Donbas region.

Putin said this "special military operation" aimed at demilitarisation. He also said that the move came in response to Ukrainian threats to pro-Russia cities. The Russian President announced military action in the Donbas area and urged Ukrainian forces to lay down their arms.

The announcement came just moments before the UN Security Council meeting to denounce the planned invasion of Ukraine.

Ukraine's foreign minister Dmytro Kuleba said:" Putin has just launched a full-scale invasion of Ukraine."

CNN reported that loud explosions were heard in the Ukrainian cities of Kyiv and Kharkiv. A "steady stream of loud explosions" were heard in Kharkiv city.

Meanwhile, Joe Biden, the President of the USA denounced Russia's advancements in the Donbas region.

In a statement, the President of the USA said:

“The prayers of the entire world are with the people of Ukraine tonight as they suffer an unprovoked and unjustified attack by Russian military forces. President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering. Russia alone is responsible for the death and destruction this attack will bring, and the United States and its Allies and partners will respond in a united and decisive way. The world will hold Russia accountable.”

Russian President Vladimir Putin warns that Moscow's response will be "instant" if anyone tries to take on Russia.