UN Secretary-General Ban Ki-moon
UN Secretary-General Ban Ki-moonReuters

United Nations (UN) Secretary-General Ban Ki-moon urged Israel on Thursday to "do far more" to spare civilians after it launched a ground offensive in Gaza.

"I regret that despite my repeated urgings, and those of many regional and world leaders together, an already dangerous conflict has now escalated even further," Ban told reporters, according to AFP.

The UN chief described as "appalling" the death of four boys killed by Israeli airstrikes on Gaza City.

"I urge Israel to do far more to stop civilian casualties. There can be no military solution to this conflict," he was quoted as having said.

Earlier Thursday, the United States urged Israel to do more to protect civilians caught in the crossfire between the Israel and Hamas.

"We ask (Israel) to redouble their efforts to prevent civilian casualties. We believe there is more that can be done," State Department spokeswoman Jen Psaki told reporters. "We believe that certainly there is more that can be done."

"The tragic event makes clear that Israel must take every possible step to meet its standards for protecting civilians from being killed," Psaki added.

IDF Spokesman Brigadier General Moti Almoz said on Wednesday that the deaths of the four children were the result of Hamas using civilians as human shields.

"Hamas is hiding among civilians targets," Almoz told Channel 2. "Hamas continues to make cynical use of civilian casualties and we will continue to operate within a civilian environment."

"As demonstrated numerous times in recent days, the IDF has no intention to harm civilians caught in the reality of fighting between Israel and Hamas," he continued.

He was backed by Finance Minister Yair Lapid, who said that it was Hamas, whose terrorists regularly uses civilians as human shields, that was responsible for the deaths of children in Gaza.

“Hamas uses these children as human shields, Israel is doing all it can to prevent such tragedies, but we are at war," Lapid emphasized. "They are also shooting at our children."