JERUSALEM (AFP) - Israel and Hamas ratcheted up the rhetoric on Monday ahead of the expiry of a six-month Gaza truce which the rulers of the Palestinian enclave say they are unlikely to renew. Top Israeli officials say the govt wants to continue the Egyptian-mediated ceasefire but also warned that it would not hesitate to use force if attacked by militants. "The minute they stop shooting rockets and terror activities against Israeli citizens, there will be no problems in Gaza... Israel is not prepared to compromise the security of its citizens," President Shimon Peres told visiting Austrian counterpart Heinz Fischer. Defence Minister Ehud Barak said Israel was willing to continue the ceasefire but would not be deterred from carrying out a military offensive. "If there is quiet it will be answered by quiet, if the calm is violated we will act accordingly," Barak's ministry quoted him as telling Fischer. Top defence ministry official Amos Gilad dismissed Hamas's claim that the truce, which went into effect on June 19, ends this week. "When we accepted a lull six months ago it was clearly understood that there was no end date," said Gilad, who had conducted the negotiations for the Egyptian-mediated truce. "For Israel, the date Dec 19 has no significance," he added. Gilad visited Cairo on Sunday for talks with Egyptian mediators but denied having gone there specifically to discuss extending the truce, which has been shaken by a flare-up in violence around Gaza since early November. The trip drew criticism from several of the Israeli government's more hawkish ministers who are demanding tougher responses to rocket attacks from Gaza. Military officials were discussing with the attorney general the legal and international ramifications of an operation inside Gaza should Hamas not renew the truce, public radio reported. Hamas political supremo Khaled Meshaal made it clear on Sunday the movement were unlikely to renew the truce. Hamas says Israel is not sticking to its side of the bargain because it has conducted attacks in Gaza and has failed to ease the crippling sanctions it imposed after the Hamas seized power . Authorities say Gaza fighters fired more than 200 rockets and mortar shells at southern Israel since Nov 4. Seventeen Palestinians have been killed in the territory during that period, while no fatality was reported on the Israeli side. Israel's mass circulation Yediot Aharonot said the military establishment believes both sides are headed towards large-scale confrontation. "It may be immediate, gradual, tomorrow or in two weeks," the newspaper added.