Kazakhstan's president, who came to power in 1990, resigns
"I have decided to resign," he said, TASS reported.
As he pointed out, the decision was not at all an easy one - but he did not specify the reasons for it.
His resignation will come into force tomorrow, Reuters is reporting.
According to the Constitution of Kazakhstan, the speaker of the upper house of the country's parliament should serve as president until the end of Nazarbayev's term in 2020.
In the last election in 2015, Nazarbayev was reelected for a five-year term with nearly 98 percent of the votes cast.
Nazarbayev has been the country's president since 1990.