International mediators are meeting in Jordan to try to save the Middle East peace plan, known as the roadmap.
Abu Mazen is trying to arrange a Hamas ceasefire
Their talks are taking place just hours after Israeli forces killed a senior leader of the Islamic militant group Hamas in the West Bank.
Abdullah Qawasmeh was shot dead by an elite army unit in Hebron on Saturday night in disputed circumstances.
Israel held him responsible for three suicide bombings this spring - one in Haifa in March and two in Jerusalem in May and June - in which about 50 people died.
The killing comes as the Palestinian Authority and Hamas finished discussions on a ceasefire.
The Palestinian Prime Minister, Mahmoud Abbas - also known as Abu Mazen - is trying to convince militants to stop their attacks on Israelis as required by the roadmap.
Abu Mazen's security chief Mohammed Dahlan said he expected a reply from Hamas within the next one or two days.
But Hamas leader Abdel-Aziz al-Rantissi - who survived an Israeli attempt to kill him earlier this month - reportedly said the militant group had not said it would reply immediately.
"Everything depends on when we are going to finish our consultations within the movement, and after that we will release our final decision," the Israeli daily Haaretz quoted him as saying.
Israel has accepted the roadmap, but it says it reserves the right to continue its hunt for militants who it says are "ticking bombs".
Mr Powell is in the region trying to bolster support for the roadmap
Israel demands that the Palestinian Authority dismantle Hamas.
The army says its forces were trying to arrest Qawasmeh, while Palestinian sources say he was shot without warning.
Israeli journalist Michael Firillas told the BBC the army had been trying to get Qawasmeh for some time.
His deputy Ahmed Badr, who was reportedly at the scene, escaped.
Amid the ongoing violence, diplomats are to discuss ways to implement the roadmap.
They are to hold discussions on the sidelines of the World Economic Forum meeting in Jordan on Sunday.
The Forum, which normally gathers political and business leaders in Davos, Switzerland, is holding a special session in Jordan to discuss the Middle East after the Iraq war.