"We plan to start exploitation of the confinement in November this year," Poroshenko said during the commemorative event to mark the 31st anniversary of the Chernobyl nuclear accident.
The Ukrainian president expressed thanks to the international donors for granting financial assistance to construct the shelter which costs 1.6 billion U.S. dollars, saying it was vital to protect humanity from the nuclear threat.
"It guarantees a minimum of 100 years of safety -- it will protect us, our children, grandchildren and great-grandchildren," Poroshenko said.
The Chernobyl disaster, one of the worst nuclear accidents in human history, happened on April 26, 1986, when a series of explosions ripped through the nuclear power plant located 110 kilometers north of the capital Kiev.
The blasts resulted in the demolition of the No.4 reactor and the spread of radiation across Ukraine, Belarus, Russia and other European countries.
Last year, Ukraine completed the four-year construction project of the arch-shaped 110-meter-tall, 257-meter-wide and 164-meter-long metal sarcophagus over the destroyed reactor.
The project, which was funded by 40 international donors, is aimed at preventing further leakage of radiation from the unit.
