Nearly a tie: Argentina and Kazakhstan differ by barely -3%% in area — about 2,782,703 km² km² against 2,712,747 km² km².
Argentina sits in South America, Kazakhstan in Asia. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 1×.
The old map muddied it further: Mercator inflates Argentina about 1.5× and Kazakhstan about 2.3×, so on a Mercator-style map this pair appears 1.5× apart instead of the true 1×.
Argentina fits 0× into Kazakhstan.