Russian President Vladimir Putin declared the launch of a "special military operation" in eastern Ukraine on Thursday, in what could be the start of a war in Europe over Russia's opposition to NATO expansion.

According foreign media outlets, Putin said Moscow has no choice but to defend itself against threats emanating from modern Ukraine, reiterating his position that NATO inclusion of Ukraine is unacceptable.

Putin said the sole objective of the operation is to protect civilians in the region, stressing that Russia has no plans to occupy Ukraine.

Stating that clashes between Russian and Ukrainian forces near the eastern Donbas region were imminent, Putin demanded that Ukrainian forces lay down their arms.

Putin said Russia would immediately respond to any external interference with unprecedented consequences and that Moscow would try to demilitarize Ukraine.