MOSCOW — In his first major speech since returning to the presidency, Vladimir Putin called on Russians Wednesday ‘‘not to lose ourselves as a nation,’’ urging them to look for guidance in Russia’s historic and traditional values — and not in Western political models — as it charts its post-Soviet development.

Putin also sent tough messages to officials in his government, warning that the prosecutor’s office had been empowered to seize illegally acquired assets. He recommended barring officials and other political figures from holding stocks and bank accounts outside Russia and said the government would begin to closely scrutinize officials’ foreign real estate holdings.