At least 23 Palestinians, including two pregnant women and a 14-month-old baby girl, have been killed since Friday.
Minnesota Congresswoman Ilhan Omar called for "real justice [to] bring about security and lasting peace" to Gaza, after Israel rocked the Strip with air strikes over the weekend.
The recent two-day outbreak of violence killed 25 people in Gaza, both militants and civilians, and four civilians in Israel.
Hamas, the Islamist group that controls Gaza, and the smaller Palestinian Islamic Jihad group fired 690 rockets at Israel. But he is under pressure from the same electorate to end its anguish and his perspective coalition partners appear to favor a more hard-line agenda on Gaza. Hamas has ruled Gaza since then, with the Palestinian Authority administering autonomous zones in the Israeli-occupied West Bank.
At least nine of those killed were confirmed to be militants affiliated with the Palestinian territory´s leaders Hamas or the allied Islamic Jihad group. The military said it also destroyed tunnels dug by the Islamic Jihad militant group to infiltrate Israel.
The Israeli military said the victim was responsible for transferring funds from Iran to armed factions in Gaza.
Mujahid said the abhorrent act came when Muslims in Palestine and the rest of the world were preparing to welcome the holy month of Ramadan.
Israel said the 34-year-old was victim of a targeted assassination, a tactic not seen since the 2014 war.
"They were a gross and blatant violation of worldwide law, and the Israeli actions to neutralize rocket launchers and prevent further attacks are entirely justified", Hoyer said in a statement. Israeli intelligence says a misfired Palestinian rocket killed them.
"Hamas and the PIJ are operating together...they have fired massive amounts of rockets at different Israeli cities", said IDF spokesperson Jonathan Conricus. Israel's army had no comment.
Israel has maintained a crippling blockade of the Gaza Strip since 2007 which critics say amounts to collective punishment of the impoverished enclave's two million residents.