At least 200 people were killed when gunmen opened fire and bombed a mosque in Egypt's volatile Sinai Peninsula on Friday, state media reported.
He said the terrorists killed innocent people, did not distinguish between children, youth or elders, and the attack was a war crime.
French Foreign Minister Jean-Yves Le Drian and British Foreign Secretary Boris Johnson also condemned the attack and expressed solidarity with Egypt.
The country's state-run MENA news agency said that 85 people have died and 80 were injured in what it described as a "terrorist incident", citing "official sources.".
At least 155 people have been killed today when suspected militants set off a bomb and opened fire at a mosque in Egypt.
President Abdel Fattah El Sisi convened an emergency security meeting soon after the attack, state television reported.
The Sinai branch is one of Islamic State's surviving branches following the collapse of its self-declared caliphate in Syria and Iraq after military defeats by US -backed forces.
Egypt has for years been battling an armed movement in the rugged and thinly populated Sinai Peninsula, which has gained pace since the military overthrew democratically elected president Mohamed Morsi of the Muslim Brotherhood in mid-2013. The crackdown has claimed scores of lives of militants whose attacks mainly targeted police and military personnel.
In October 31 2015 ISIL-SP destroyed a Russian plane carrying 224 passengers, all of whom perished in the explosion.
US President Donald Trump: "Horrible and cowardly terrorist attack on innocent and defenseless worshipers in Egypt".
UK Prime Minister Theresa May: Appalled by the sickening attack on a mosque in North Sinai. "My honest condolences to all those affected by such a barbaric act", he tweeted.
View of the Rawda mosque after a gun and bombing attack on November 24, 2017. We can not & will not allow terrorists to win.