"There is and can be no justification for such attacks against innocent civilians. The thoughts and prayers of the American people are with the victims and families of all those who were killed and injured in this horrific attack and in other recent violence."
The Americans killed were identified by the White House as Aryeh Kupinsky, Cary William Levine, and Mosheh Twersky.
The attack occurred at a synagogue in the Har Nof neighborhood of West Jerusalem when two men, armed with a gun, knives and axes, stormed the religious facility. Police shot and killed both assailants.
Tuesday's attack is the latest episode of violence amid rising tensions in the city. In the past month, Jerusalem has been the site of violent clashes between Palestinians and Israelis over access to the Temple Mount holy site, also known as Al Haram Al Sharif, and two attacks by Palestinians who drove their vehicles into pedestrian crowds.
U.S. Secretary of State John Kerry, following a trilateral meeting with Israeli Prime Minister Benjamin Netanyahu and King Abdullah II of Jordan last week in response to rising tensions, was optimistic that "specific actions" had been agreed to that would "restore calm" in Jerusalem. Kerry would not say what those actions were.
"At this sensitive moment in Jerusalem, it is all the more important for Israeli and Palestinian leaders and ordinary citizens to work cooperatively together to lower tensions, reject violence, and seek a path forward towards peace," Obama said Tuesday.