Omar Suleiman had announced Thursday he wouldn't seek the presidency due to a "difficult political situation and because [he] cannot fulfill the conditions required to become an official candidate," Ahram Online reported.
He backtracked Friday, though, saying he would run for office after supporters rallied earlier in the day in the Abbasiya district of Cairo, The Washington Post reported.
"I cannot refuse people's will. Even though I said in my previous statement that I will face a lot of troubles and difficulties," Suleiman said in a statement Friday.
Suleiman's announcement comes one day after the Muslim Brotherhood's Freedom and Justice Party officially nominated Khairat Al-Shater for the presidential election.
Thousands of Muslim Brotherhood supporters, mostly young people, gathered in Cairo to celebrate Al-Shater's candidacy, chanting: "They called us defectors, then who are we? We are the Muslim Brotherhood," Daily News Egypt reported.