The attack in Sinai brings to the surface a largely unreported war against terror that has gone on in the peninsula for years.
No group immediately claimed responsibility, but since 2013 Egyptian forces have battled a stubborn Islamic State affiliate in the region.
Abbas last met Sisi on the margins of the United Nations General Assembly in September.
Reports of the meeting were nowhere to be found on Al-Jazeera as of 10am Jerusalem time, eight hours after it happened and six hours after photos from the sit-down were released.
Prime Minister Benjamin Netanyahu: Trump, like Israel but unlike Obama, sees Iran as problem in Mideast, not solution.
Both Egypt and Saudi Arabia share a sense of satisfaction with the advent of the Trump administration, which they see as reversing Obama policies that harmed them.
The London-based newspaper Al-Quds Al-Arabi reported that the Israeli delegation arrived in a special plane that left Tel Aviv’s Ben-Gurion.