"We need to support efforts by the international community to strengthen Jordan and support the aspirations of the Kurds for independence," Netanyahu said in a speech to the Institute of National Security Studies (INSS) think-tank in Tel Aviv.
"I think it's our common interest to make sure that a moderate, stable regime like (Jordan) is able to defend itself," he added.
His remarks follow reports in Israeli media that officials in Tel Aviv fear Islamic State of Iraq and the Levant (ISIS) extremists may extend their control to areas of Jordan after seizing parts of Iraq in recent weeks.
Earlier on Sunday, former National Security Council director Yaakov Amidror warned against ISIS moving in on Jordan and posing a threat to Israel, adding that if Jordan requested Israeli assistance in preventing its border with Iraq from being overrun by ISIS, Israel would have little choice but to help.
In Syria, ISIS fighters already control large swathes of territory in Deir Ezzor near the Iraq border, Raqa in the north, as well as parts of neighboring Aleppo province.
In Iraq, they have spearheaded a lightning offensive, capturing sizeable territories in the north and west of the conflict-torn country.
Netanyahu also called for independence for Iraq's Kurdistan region, where Kurdish peshmerga security forces have mobilized in an unprecedented deployment to fight against ISIS.
The premier voiced concern over "the powerful wave triggered by ISIS, which could reach Jordan in a very short time."
He added, "We must be able to stop the terrorism and fundamentalism that can reach us from the east at the Jordan line and not in the suburbs of Tel Aviv."
ISIS on Sunday declared it had established a "caliphate", or Islamist state, straddling Iraq and Syria.