Israel and Hamas have been engaged in a deadly exchange of airstrikes for more than two weeks.
An Egyptian proposed cease-fire initiative is currently on the table.
Speaking from Cairo on Tuesday, U.S. Secretary of State John Kerry noted that while Israel has accepted the cease-fire proposal, Hamas has not yet agreed to it.
"Hamas has a fundamental choice to make and it is a choice that will have a profound impact for the people of Gaza. And the Egyptians have provided a framework and the forum for them to be able to come to the table to have a serious discussion together with other factions of the Palestinians. And President Abbas has been here in Israel, other countries, talking with leaders in order to try to encourage the Palestinian people to be able to come together around a solution to this crisis."
Hamas has so far rejected the peace proposal, citing unmet demands such as the end of the Israeli naval blockade of Gaza and releasing hundreds of Hamas prisoners.
The 16-day conflict has inflicted mass casualties, mostly on the Palestinian side, prompting Kerry and United Nations Secretary-General Ban Ki-moon to publicly question the proportionality of Israeli's airstrikes.
630 Palestinians have been killed since July 8, 70 percent of whom the U.N. says were civilians. Israel reported 27 soldiers killed and two civilians.
Kerry arrived in Israel a day after the U.S. Federal Aviation Administration announced that all American carriers must cancel their flights to and from Israel's Ben Gurion International Airport for a 24-hour period after a rocket strike landed one mile from the airport Tuesday morning. Because Kerry traveled via a U.S. Air Force plane, he was not restricted by the ban on commercial airline travel.