President Abdel Fattah El Sisi convened an emergency security meeting soon after the attack, state television reported.
In response to the most recent terror attack on USA soil, in NY on October 31, Trump said that: "We're so politically correct that we're afraid to do anything".
According to the TV network, the mosque was attacked during the Friday prayer in the Al Rawdah inhabited community near the city of Arish, the capital of North Sinai Governorate.
The attack was unusual in several ways for Egypt, said Kamran Bokhari, senior analyst at George Washington University's Program on Extremism: the high casualty toll, targeting a mosque and its level of sophistication. Our deep condolences at the loss of innocent lives. "God bless the people of Egypt".
"Horrible and cowardly terrorist attack on innocent and defenseless worshipers in Egypt", Trump wrote on Twitter. "The world can not tolerate terrorism, we must defeat them militarily and discredit the extremist ideology that forms the basis of their existence!"
Trump Returns North Korea to List of State Sponsors of Terrorism
In any case, it will do little to open the way for USA dialogue with North Korea, which China and others have been pushing for. Cuba had been on the list but was removed by President Barack Obama in 2015. "The North Korean regime must be lawful".
North Sinai, which stretches from the Suez Canal eastwards to the Gaza Strip and Israel, has always been a security headache for Egyptian security forces because of smuggling. Condolences with all those in #Egypt affected by this evil and cowardly act. "We can not & will not allow terrorists to win", Pence tweeted. "This terrorist act will strengthen our resolve, steadfastness and will to stand up to, resist and battle against terrorism".
"What is happening is an attempt to stop us from our efforts in the fight against terrorism, to destroy our efforts to stop the bad criminal plan that aims to destroy what is left of our region".
Unidentified terrorist stormed Al-Rawda mosque early on Friday with explosives and heavy weaponry during the Friday prayers and opened fire on worshippers. Around 40 gunmen set up positions outside the mosque with jeeps and opened fire from different directions as people tried to escape.
The official Al-Ahram newspaper reported on its website that at least 115 people were killed and 80 wounded in the attack, which is unprecedented in a four-year insurgency by Islamist extremist groups.
The victims were reportedly being transported to hospitals to be treated. They also blocked off escape routes from the area by blowing up cars and leaving the burning wrecks blocking the roads, three police officers on the scene said, speaking on condition of anonymity because they were not authorized to talk to the press.