In a televised address, he accused the West of engaging in "nuclear blackmail" against Russia and of seeking to destroy his country, the Reuters news agency reported.
Putin said his aim was to "liberate" eastern Ukraine's Donbas region, claiming that most people in areas under Russian control did not want to be ruled by Kyiv, according to Reuters.
He warned that Russia had "lots of weapons to reply" to what he described as Western threats and said that he was not bluffing, Reuters reported.
Russia's Defence Minister Sergei Shoigu was quoted as saying that the partial mobilisation would see 300,000 reservists called up and would apply to those with previous military experience.
Top Ukrainian officials said on Tuesday that plans by Russian-installed authorities in occupied parts of Ukraine to hold referendums on joining Russia “will not change anything” and "stem from fear of defeat.”
Source: IAR, PAP, Reuters