Live: Kyiv declares martial law as Russia launches 'special military operations' in eastern Ukrai

Ukrainian President Volodymyr Zelenskyy on Thursday morning declared martial law and says Russia has launched strikes against border and military infrastructure.

Big explosions were heard before dawn in Kyiv, Kharkiv and Odesa as world leaders decried the start of an Russian invasion that could cause massive casualties and topple Ukraine’s democratically elected government.

Putin justified the assault on Ukraine in a televised address, arguing it is needed to protect civilians in eastern Ukraine — a false claim the U.S. had predicted he would make as a pretext for an invasion. He accused the U.S. and its allies of ignoring Russia’s demand to prevent Ukraine from joining NATO and offer Moscow security guarantees, and credulously claimed that Russia doesn't intend to occupy Ukraine but will move to “demilitarize” it and bring those who committed crimes to justice.

He warned other countries that any attempt to interfere would lead to “consequences you have never seen.”

US President Joe Biden says the world will “hold Russia accountable," and NATO's head called Russia's action a violation of international law and a threat to the security of Europe and its Atlantic allies.

Zelenskyy had earlier said in an emotional televised address to the nation that he had "sought a telephone call with the president of the Russian Federation (Vladimir Putin, ed). The result: silence."