Nikolai Lazovik said the deadline for submitting signatures was January 27.
Incumbent president Alexander Lukashenko's initiative group gathered 1.9 million signatures in support of his candidacy, the largest number of signatures.
Lukashenko, dubbed "Europe's last dictator" by the Western media, has ruled Belarus since 1994.
Opposition candidate Alexander Milinkevich's group gathered 198,559 signatures, social democrat party Gramada leader Alexander Kozulin's group gathered 156,618, and liberal democrat leader Sergei Gaidukevich's group submitted 150,319 signatures.
The groups of two other candidates, former deputy Valery Frolov and Belarusian People's Front leader Zenon Poznyak submitted 58,775 and 719 signatures respectively.
The Central Election Committee only registers candidates with 100,000 or more supporting signatures.