"We in Hamas haven't heard about the Egyptian suggestions except on media outlets. Nobody has consulted us about this initiative, and so it is natural that the initiative isn't binding to us."
"We fought in order to end oppression practiced against our people in general and the people of Gaza in particular, and ceasefire wasn't our goal when we fought," Abu Zuhri said.
The Hamas official condemned international and regional support for the ceasefire initiative, explaining that if one of the sides involved in the conflict is not consulted it is "worthless."
Islamic Jihad said the group was officially notified about the Egyptian initiative but will agree with Hamas on a joint response.
Gaza spokesman Yousif al-Hasaynah said the group had reservations because it had not taken part in the wording of the ceasefire and will not agree to it without Hamas' approval.
US Secretary of State John Kerry has urged Hamas to accept Egypt's ceasefire proposal to halt fighting with Israel in the Gaza Strip.
"The Egyptian proposal for a ceasefire and negotiations provides an opportunity to end the violence and restore calm," Kerry said.
Arab foreign ministers in Cairo early Tuesday called on "all parties" to accept an Egyptian proposal to end the raging conflict between Israel and Hamas.
Over 190 Palestinians and been killed in Israel's ongoing assault on Gaza, with at least 1,400 injured.