"Israel will continue to act to protect its citizens," he told the Reuters news agency on Friday.
The same day, thousands of supporters of Hamas protested in Gaza against Israel's refusal to accept the truce.
There were protests in the north and south of the enclave near border crossings into Israel and Egypt.
In Jabaliya, in northern Gaza, about 5,000 people waved Hamas flags and banners proclaiming "No to the siege".
Yussef al-Shrafi, a Hamas official, told the crowd: "Hamas is working in a positive manner to end the siege and achieve a truce."
In Rafah, about 1,000 people called for Egypt to open its border crossing, the only one that bypasses Israel.
"We do not represent a threat to Egypt's security, but we ask our brothers to open Rafah and break the siege," said Abu al-Sibbah, a Hamas leader.
Al Jazeera's David Chater, reporting from Gaza, said the protests were an attempt by Hamas to put pressure on Israel to lift its blockade.
"In a way, Hamas is showing its power - it's moved thousands of people to two of the crossing points, one by Israel and one by Egypt," he said.
"And I suppose, behind it is the threat that once against they will attempt to storm these crossing points if and when the Israelis decide they are not going to change their attitude and lift the suffocating siege of the Gaza Strip."