"I have taken a decision, which was not easy for me, to resign as president", Nazarbayev said in a televised address before signing a decree terminating his powers from March 20.
Nazarbayev, born in 1940, served as the first president of Kazakhstan from 24 April 1990, the day the country was formed following its independence from the Soviet Union.
Kazakhstan, where 60% of the population is under 30, has never had a leader other than Nazarbayev, who was popular and successful in the nation-building effort, including the building of the new capital, Astana, of which Kazakhs are proud.
The question of succession has dogged Nazarbayev for years as his political opponents ended up in exile, political oblivion, jail or a graveyard.
"Although Nazarbayev will retain some key roles, his decision to resign will doubtless slow policy-making as political dynamics are restructured", Scargill said.
Kremlin spokesman Dmitry Peskov said that Russian President Vladimir Putin Putin had spoken with Nazarbayev by telephone earlier Tuesday but didn't say what they had discussed.
Nazarbayev inherited one of the world's largest nuclear arsenals after the collapse of the Soviet Union, but dismantled the weapons within years of taking power.
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Professor Migranyan pointed out that "it would be against Kazakhstan's economic interests to spoil relations with Russia" as the trade turnover between the two nations reached $17,6 billion past year.
Tokayev, 65, is a Moscow-educated career diplomat fluent in Kazakh, Russian, English and Chinese who has previously served as Kazakhstan's foreign minister and prime minister. In April 2015, he was re-elected with nearly 98% of the vote and he also holds the title of "Leader of the Nation". "He participated in the development and adoption of all programs", Nazarbayev said.
Another possible future leader of the country is Karim Masimov, 53, who was prime minister twice and also served as Nazarbaev's chief of staff.
He remains president of the National Security Committee of the Republic of Kazakhstan and chairman of the Nur Otan Party.
Nazarbayev has been widely praised for maintaining stability and ethnic peace in Kazakhstan but he also has faced criticism for marginalizing the political opposition and creating what is effectively a one-party state.
Nazarbayev's eldest daughter, Dariga, the most politically ambitious of his children, is a senator and once led a political party of her own.
Geographically, Kazakhstan has benefited by linking markets of China and South Asia and those of Russian Federation and Western Europe by road, rail, and a port on the Caspian Sea.
But the conduct of every election was criticised by foreign observers.