"There is no doubt the Holy Father will maintain his offer to go to Egypt" on April 28 and 29, Monsignor Angelo Becciu, the Holy See's number three, said in an interview published in the Italian daily Corriere della Sera on Monday.
"What happened caused disorder and tremendous suffering, but it cannot stop the pope's mission of peace," he added.
Sunday's bombings in churches in the Mediterranean city of Alexandria and Tanta north of Cairo were the deadliest attacks on the Coptic Christian community in recent memory and were claimed by the Islamic State group.
Copts make up about 10 percent of Egypt's 92 million people, the largest Christian minority in the Middle East. The community has long faced discrimination, sectarian violence, and state repression.
Becciu, who will travel to Egypt with the pontiff, described the bombings as an "attack on dialogue, on peace".
"Egypt has assured us that everything will go as well as possible, so we will go confidently," he said.
The pope had also voiced his condolences on Sunday for victims of the double bombing, which has led Egypt to declare a three-month state of emergency.
"May the Lord convert the heart of those who sow terror, violence and death and also the heart of those who make weapons and trade in them."
Francis will become the second Roman Catholic pope to visit Egypt, following John Paul II's historic trip there in February 2000.
The Vatican's slogan for the trip is "Pope of peace in Egypt of peace"
