The efforts of the US are focused on "using all tools at our disposal to bring an end to the rocket fire that is threatening the innocent lives of civilians in Israel and that is certainly posing a threat in the region", State Department spokeswoman Jen Psaki told a press briefing Thursday.
Israeli started Tuesday a military operation to curb fire rockets from Gaza over the past few days.
As of Thursday afternoon, the Israeli Air Force struck down about 800 targets in the Gaza Strip, killing 81 Palestinians and injuring more than 500 others, according to Palestinian medical sources.
Psaki said US Secretary of State John Kerry had spoken by phone with both Palestinian President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu, restating the willingness of the US to engage robustly in helping to stop the rocket fire of Hamas in order to "restore calm as soon as possible", Xinhua reported.
Psaki emphasised that Hamas is at fault to launch "indiscriminate" attacks against Israel and Israel is "exercising its right to self-defence".
The spokeswoman also noted that Israel has taken steps to try to prevent civilian casualties by providing warning in advance, and "that is not what, of course, Hamas is doing".
"It's in everyone's interest to deescalate the situation, to prevent a ground invasion or a ground component of this, and to save the lives of innocent civilians," Psaki added.
US President Barack Obama, in a telephone talk with Netanyahu Thursday, reiterated the US's strong condemnation of continuing rocket fire into Israel by Hamas and other terrorist organisations in Gaza and reaffirmed Israel's right to defend itself against these attacks.
Obama expressed concern about the risk of further escalation and emphasised "the need for all sides to do everything they can to protect the lives of civilians and restore calm", according to a statement issued by the White House.
The US remains prepared to facilitate a cessation of hostilities between Israel and Hamas, including a return to the November 2012 ceasefire agreement, said the statement.