"I see now there is a real chance for change… War is not within our interests," Sinwar told Italy's Repubblica newspaper.
Sinwar blamed Israel for the worsening the humanitarian situation.
"Those who have closed the borders, rather than those who try to open them, are to blame. I am responsible for cooperating with anyone who wants to help us and put an end to the blockade. An outbreak is inevitable now," the leader said.
Gaza is ready to sign and implement a ceasefire, but when the enclave is attacked, it has to defend itself, Sinwar added.
Sinwar, one of the leaders of the Izz ad-Din al-Qassam Brigades, Hamas' military wing, had served over 20 years in prison in Israel on charges of terrorism before being released in 2011 in exchange for Israeli soldier Gilad Shalit, kidnapped by Hamas militants in 2006.
Hamas seeks the creation of an independent state of Palestine and wants Israel to withdraw from the Palestinian territories it occupied after the 1967 war. The movement governs the Gaza Strip independently of the Palestinian Authority.