"There have been no mediation efforts serious enough to warrant the blood of our martyrs," Hamas spokesman Fawzi Barhoum told Anadolu Agency.
"We are facing a war by Israel on the Palestinian people," he said.
At least 100 Gazans, mostly civilians, have been killed and hundreds injured since Monday in a series of Israeli airstrikes.
Israel's military offensive, dubbed "Operation Protective Edge," is ostensibly aimed at ending rocket fire from Gaza.
Gaza-based resistance factions, meanwhile, have continued to fire rockets into Israel – without causing any fatalities thus far – in response to the unrelenting airstrikes.