"I give my word: they will be held before the end of the year," he told El Mundo newspaper in an interview published on the eve of his official visit to Spain.
Egypt's parliamentary polls were set to start on March 21 and run until May 7 but were postponed after the constitutional court ruled that parts of the electoral law unconstitutional.
The election would be the first for a new parliament since former army chief Sisi overthrew Islamist president Mohamed Morsi in 2013.
"I faced a difficult equation: my role is to guarantee life and security of 90 million Egyptians who faced the risk of chaos. If I let anything be done, is it Europe that would pay the salaries of Egyptians?" he said.
"Don't judge me without taking into account the reality on the ground," he added.
"If the state collapses, that would cause terrible harm to Europe and the region would face a disaster. Egypt is not Iraq, or Syria or Yemen, nations that each have over 20 million residents. We are 90 million.
"Egyptians can break with al-Sisi if they wish. If I had not intervened, there would have been a civil war."
Sisi refused to answer a question about Egypt's first freely elected leader, Mohamed Morsi, who was sentenced last week by an Egyptian court last week to 20 years in prison for abuses against protesters.
Morsi, an Islamist, came to power following the 2011 ouster of longtime autocrat Hosni Mubarak in a popular uprising.
But after just a year in power, Morsi was himself toppled by then-army chief Sisi following mass street protests.
