Islamic Jihad had said on Thursday it would stop rocket attacks if Israel ended the Gaza offensive that has killed hundreds of Palestinians.
An Israeli official immediately rejected the suggestion and demanded that Palestinian fighters lay down their weapons first.
Güncelleme Tarihi: 20 Eylül 2018, 18:16
Miri Eisin, the government spokeswoman, said on Friday: "The suggestion concerns a partial ceasefire, limited to rocket fire from the Gaza Strip in exchange for a total halt to Israeli operations on all fronts. This is not serious.
"There is no commitment on the part of armed Palestinian groups to put an end to terrorist operations and suicide attacks in particular.
"Israel has always aspired to an end to violence, and we count on a change of attitude from the Palestinians and primarily Hamas in order to give development a priority in the Gaza Strip instead of continued attacks."
Khader Habib, a spokesman for the Islamic Jihad said: "We talked [with Palestinian groups] about the rocket fire. There is an agreement to stop the fire in exchange for a halt to Israeli aggression against the Palestinian people in the West Bank and Gaza."
He said that the main Palestinian factions, including the governing Hamas, the Fatah movement of Mahmoud Abbas, the president, and other smaller groups had agreed the ceasefire offer during a meeting with Ismail Haniya, the Palestinian prime minister.
On Wednesday, the Israeli government decided to press on with a five-month-old offensive launched after militants seized a soldier in a cross-border raid from the Gaza Strip last June.
More than 380 Palestinians have been killed since the offensive began. One Israeli has been killed by rocket fire in the same period.