Trump denounces Egypt mosque attack on 'innocent, defenceless worshippers'
"The world cannot tolerate terrorism" and that "we must defeat them militarily and discredit the extremist ideology that forms the basis of their existence!" Trump said on Twitter.
His tweet came as he was playing golf at one of his Florida courses with Tiger Woods and Dustin Johnson.
Separately, the US president called his counterpart Abdel Fattah al-Sisi to offer hiscondolences.
A White House readout of his call with Sisi said he "condemned the attack and reiterated that the United States will continue to stand with Egypt in the face of terrorism."
"The international community cannot tolerate barbaric terrorist groups and must strengthen its efforts to defeat terrorism and extremism in all its forms," it added.
A bomb explosion tore through the Rawda mosque in Egypt's restive North Sinai province, and then armed attackers raked fleeing worshipers with gunfire.
Islamic State group militants are suspected of carrying out the attack, and fighters have led an insurgency against security forces in the area.
State media put the death toll at 235. The mosque, located roughly 40 kilometres (25 miles) west of the North Sinai capital of El-Arish was attended by sufis, who are considered heretics by the Islamic State group.
Also on Friday, Israel offered condolences to Egypt over the attack.
On Friday, the Eiffel Tower in the French capital Paris went black at midnight in homage to the victims of the deadly assault.
Paris' mayor Anne Hidalgo offered her "condolences to the victims' families" and her "support to the people wounded" via Twitter.
She said that turning off the lights at the famed Paris monument would send a message of solidarity from the French capital that has itself been the site of a spate of deadly extremist attacks in recent years.
French President Emmanuel Macron also went to Twitter to send his "condolences to the victims of the terrible attack".
The UN Security Council and Secretary-General Antonio Guterres had earlier condemned the deadly attack on a mosque in Egypt’s Sinai Peninsula in "the strongest terms" and called for the perpetrators to be brought to justice.
Agencies contributed to this report.