Kazakhstan to hold early elections in June
The only other potential heavyweight candidate, Dariga Nazarbayeva, has no plans to run, her aide told Kazakh news website Tengrinews.kz after the vote announcement.
Her father Nursultan Nazarbayev ran the ex-Soviet republic for almost three decades until his surprise resignation last month. Tokayev, then speaker of parliament's upper chamber, subsequently assumed the presidency.
The announcement of a snap election in two months leaves other potential candidates with little time to organize and run campaigns. The incumbent's ratings are likely to benefit from public sector pay rises in June and other welfare initiatives.
"In order to secure social and political accord, confidently move forward, and deal with socio-economic development tasks, it is necessary to eliminate any uncertainty," Tokayev, 65, said in a televised address to the nation.
Nazarbayev, 78, retains sweeping powers in the country of 18 million as the official "national leader", chair of its security council and head of the ruling Nur Otan party. Analysts say his endorsement will be the deciding factor in the vote.
Nazarbayev's daughter Dariga, 55, also regarded by analysts as a potential president one day, has replaced Tokayev as Senate speaker.