The British Foreign Secretary was speaking to reporters in East Kilbride, Scotland on Monday (11 February).
The comments came after airstrikes in southern Gaza killed over 100 Palestinians, according to local health officials.
The city is the last refuge of around one million displaced civilians.
“We are very concerned about the situation and we want Israel to stop and think very seriously before it takes any further action. But above all, what we want is an immediate pause in the fighting and we want that pause to lead to a ceasefire,” Lord Cameron said.