The U.S. and the United Nations condemned the resumption of hostilities between Israel and Hamas in the Gaza Strip after the expiration of a three-day cease-fire agreement Friday. Four mortar shells hit the Israeli town of Eshkol, near the Gaza border, and a missile was fired at the Sdot Negev Regional Council building, in the southern district of Israel, early Saturday.

The U.S. and the U.N. reactions came on the heels of the resumption of attacks between the two sides. White House Press Secretary Josh Earnest said Friday that both of them should resolve to secure a “sustainable cease-fire,” BBC News reported. More than 1,900 Palestinians and 67 Israelis have been killed during the violence of the past four weeks, according to U.N. estimates.

“Its [Hamas’] decision to resume rocket fire puts the people of Gaza at greater risk and will do nothing to meet the expectations of the Palestinian people. So we hope we can get back to a cease-fire here,” Marie Harf, deputy spokesperson at the U.S. State Department, said at a briefing Friday. She added, “What we’re looking at right now is how to get an extension of this temporary cease-fire, but then a more sustainable long-term cease-fire in place.”

U.N. Secretary-General Ban Ki-moon asked the parties to “swiftly” reach agreement on a truce in negotiations that are being brokered by Egypt.

“The secretary-general expresses his deep disappointment that the parties were unable to agree to an extension of the cease-fire in their talks in Cairo. He condemns the renewed rocket fire toward Israel. More suffering and death of civilians caught up in this conflict is intolerable,” Ki-moon’s representative said in a statement Friday. “The extension of the cease-fire is absolutely essential for talks to progress and to address the underlying issues of the crisis as soon as possible. The secretary-general firmly calls on the parties not to resort to further military action that can only exacerbate the already appalling humanitarian situation in Gaza.”

The Israeli Defense Forces claimed via Twitter that 43 rockets were fired at Israel from Gaza since the temporary cease-fire expired and said it struck back with airstrikes on “70 terror sites” in response. Meanwhile, Hamas said the Palestinian group is willing to continue truce talks in spite of the fresh violence, BBC News reported.