Billionaire Andrej Babis has been appointed as the Czech Republic's new prime minister, with his full cabinet expected to take office within days.

His appointment followed a key demand from President Petr Pavel - a public pledge by Babis to relinquish control over his vast food-processing, agriculture and chemicals conglomerate Agrofert.

"I promise to be a prime minister who defends the interests of all our citizens, at home and abroad," Babis said after the ceremony at Prague Castle.

"A prime minister who will work to make the Czech Republic the best place to live on the entire planet."

These are lofty ambitions, but Babis, 71, is used to thinking big.