"The field marshal made his final decision and he will officially announce it to the public at the end of this month," Xinhua quoted Moussa as saying.
Moussa, who joined the presidential race of 2012 and served as the former minister under toppled president Hosni Mubarak, repeatedly voiced his support for the military chief, urging him to run in the upcoming presidential elections to be held in mid- April. Moussa himself said he will not run for the 2014 presidential race.
Since Sisi led the ouster of former Islamist president Mohamed Morsi last July, his popularity has grown in the turmoil-stricken country with many of his supporters calling on him to run for president.
The military chief has neither confirmed nor denied his intention to compete in the upcoming presidential race.
Although, in January, Sisi said that if he runs for president, his candidacy would be based on "popular demand and a mandate from the army".