Secretary of State John Kerry yesterday also condemned the shooting of hardline rabbi Yehuda Glick, who holds both Israeli and US citizenship.
Kerry called for the reopening of the Al-Aqsa mosque in Jerusalem to Muslim worshippers as police said the compound would open early today for dawn prayers.
"I am extremely concerned by escalating tensions across Jerusalem and particularly surrounding the Haram al-Sharif/Temple Mount," Kerry said in a statement.
Kerry said he was in close contact with Israeli, Jordanian and Palestinian leaders to try to de-escalate the situation.
"I urge the leaders of all three parties to exercise decisive leadership and work cooperatively together to lower tensions and discourage violence," he said.
State Department spokeswoman Jen Psaki said earlier Kerry was expected to be in touch with Israeli Prime Minister Benjamin Netanyahu in the next 24 hours.