Is it permissible to utilize the government assistance provided to families in Russia, amounting to 450,0 rubles, to pay off an interest-based (riba) bank loan designated for improving housing conditions, given that the government pays the full amount directly to the bank?

It is absolutely impermissible to borrow with interest (riba), even if the government pays the interest, because every loan that draws a benefit is usury (riba), which is prohibited by the consensus of scholars. Usury is one of the gravest major sins, and Allah has threatened those who consume it with war from Him and His Messenger. The Prophet (peace be upon him) cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses. Usury is only permitted in a dire necessity that compels one, and the need for housing is not considered a necessity because it can be met by renting. A Muslim must be patient and seek lawful sustenance.