His decree follows the parliament's approval of a package of laws allowing the vote to proceed.
The snap elections are part of a deal reached on May 27 by Yushchenko and his rival, Prime Minister Viktor Yanukovych, to end a two-month political standoff.
Yanukovych and his parliamentary majority had initially defied Yushchenko's April 2 order to dissolve parliament and call early elections.
(AFP, Interfax, ITAR-TASS)
