How do Ukraine's military capabilities measure up against Russia?

Ukraine’s President Volodymyr Zelenskyy warned Russia after it launched an attack on the country overnight Wednesday that for the sake of Ukrainians "freedom," "lives" and their "children’s lives we will defend ourselves."

Moscow has Kyiv both outgunned and outmanned – with at least three times the tanks of Zelenskyy’s defense forces, according to Reuters. Russia has around 900,000 active-duty troops in all branches of the military compared to less than 200,000 for Ukraine, Britain’s Sky News reported. 

Zelenskyy called up the country’s reservists this week, of which there are about 900,000, according to Sky News, compared to Russia’s 2 million. Ukraine also has volunteer territorial defense units around the country.