The Egyptian President has vowed to build the largest church in Egypt.

President Abdel Fattah al-Sisi said he has put aside 100,000 Egyptian pounds for the project, which will also include the building of a large mosque.

He made the announcement during a Christmas liturgy held at Cairo's Coptic Orthodox Cathedral, celebrated by Patriarch Tawadros II.

The President also reiterated his commitment to rebuild churches which were damaged or destroyed during the 2013 riots after former Islamist President Mohammed Morsi was deposed.

More recently, Sisi has overseen the rebuilding of Cario's Boutrossiya chapel, was badly damaged in December when a suicide bomber killed 27 people.

Patriarch Tawadros II called the attack "not just a disaster for the church but a disaster for the whole nation".

Those killed in the blast were given a state funeral, attended by Sisi.

Last year Sisi praised Egyptian Christians for demonstrating "wisdom and a spirit of patriotism" and praised them for remaining united in the face of those who "try to exploit religion as a means of fomenting division and spreading extremist ideas".

Tensions between Christians and Muslims have intensified in Egypt since the Arab Spring of 2011.

The worst single incident came in February 2015, with the beheadings by Islamic State of 21 Egyptian Christian migrant workers.

Egypt has an estimated population of 9 million Christians. Mostly Orthodox Copts, they account for about 10 per cent of Egypt's population, which is overwhelmingly Sunni Muslim.