"Has terrorism ended? No... Whoever downed that plane, what did he want? Just to hit tourism? No. To hit relations. To hit relations with Russia," Sisi said in a speech.
Previously, Sisi had dubbed as "propaganda" a claim by the Islamic State (IS) jihadist group that it was involved in bringing down the ill-fated plane on October 31.
The IS had then said that a bomb was smuggled by their members on board the plane in the airport of Sharm el-Sheikh, a Sinai resort popular with Russian holidaymakers.
It is to be noted that Russia had concluded after few days that a bomb brought down the airliner, and suspended flights to Egypt. Britain also followed suit, stopping flights to Sharm el-Sheikh.
A committee has been set up by the Egyptian government to investigate the attack. Cairo had previously insisted it be allowed to finish its probe before any conclusions were made. Egyptian media outlets have also rejected the IS's claims, stressing that the claim of bomb attack was part of a Western "conspiracy" aimed at harming the country's tourism sector.
The A321 airliner was operated by Russia's Metrojet and was on its way to Saint Petersburg when it broke up mid-air over the Sinai, minutes after take-off. The wreckage of the plane fell several kilometres (miles) across North Sinai.