Egyptian President Abdel-Fattah El-Sisi has opened the Gaza aid conference by emphasising that this generation should work for a peaceful existence in the Middle East.

El-Sisi described the conference in Cairo as "an inevitable step,'' and praised international leaders for "accepting the invitation" and attending such a gathering in order to "assert our solidarity with the Palestinian people in its crisis."

"We assert at today's conference our support for the Palestinians and their legitimate government so they can rebuild the Gaza Strip, which represents a crucial part of Palestine," he added.

Egypt made "tireless efforts" to conclude a Palestinian-Israeli ceasefire agreement during the recent Israeli offensive.

The president said these endeavours had continued even after the announcement of an armistice deal as Egypt had backed the implementation of the agreed terms and conditions.

He also stated that Cairo had worked to end inter-Palestinian divisions and return the Palestinian Authority (PA) to Gaza in order to "emphasise the unity of the Palestinian territories."

Egypt has provided humanitarian support to the Palestinian people in Gaza, El-Sisi said.

"We will continue to back the Palestinian cause, accentuate its importance and make it a priority for the Arab world," he stated.

"Egypt is working to end the tragic conditions in Gaza by fulfilling the needs of its people. This can happen through a permanent truce and the PA's governance of the Strip."

El-Sisi underlined the need for a "just and comprehensive settlement" to the Palestinian-Israeli conflict.

"There is no alternative to such a settlement for the Palestinians."

Israel's people and government must "end the conflict," he added.

"That [ending the conflict] is our duty towards the coming generation, and we hope the results of this conference can meet the ambitions of the Palestinians."

"We have supported all previous efforts for peace in the Middle East, and we appreciate the efforts of the United States for Palestinian-Israeli peace that failed last April," El-Sisi concluded.

Abbas says Gaza needs $4 bln for reconstruction

President Mahmoud Abbas asked the international community to help the Palestinians in rebuilding the devastated and besieged Gaza Strip and to exert more pressure on Israel to end its occupation of the Palestinian lands.

In his speech at the opening of a high-profile conference aiming to raise billions of dollars to help rebuild the devastated Gaza Strip, Abbas hailed the Egyptian government for hosting the conference and for the efforts exerted to achieve the ceasefire after the 51 day Israeli offensive on Gaza.

"The devastated enclave needs urgent help to begin the process of rebuilding and reconstruction. The Western-backed Palestinian president said that the Israeli occupation never abandoned its plans of further occupation of the Palestinian lands."

Abbas expressed his wish to longer hold the biannual conference, saying that despite its recurrence, war continues to take place.

Abbas added that the destruction caused by the latest Israeli offensive is unbearable and that Israel should be held accountable.

The Palestinian president asked the international community to prevent Israel from launching any new attack on the enclave.

The Gaza Strip has been subject to three wars within the past six years that claimed 3,760 lives, 2,145  of which were taken in the latest offensive. The number of people injured reached 18,100.

About 100,000 housing units were destroyed or damaged to varying degrees. Of those, about 20,000 homes were destroyed or severely damaged in the most recent offensive.

 More than 100,000 people are still displaced, with about 57,000 living in communal shelters.

Abbas said that his government is now in dire need to help rebuilding the governmental institutions that will be run by the unity government.

Abbas also called for the opening of the crossing-borders between Gaza and the other parts of Palestine and between Palestine and neighboring countries.

 "According to a plan prepared by the Palestinian government, the construction operations require $4 billion. The unity government will work on implementing the plan with the United Nations and civil society organizations," Abbas added.

Abbas also hoped that Israeli authorities allow Palestinians to make use of the lands of the occupied West Bank as Israel prevents them from doing any kind of development or investments in more than 60 percent of this territory.

UN chief calls for implementation of two-state solution

In his speech, UN Secretary-General Ban Ki-moon said he hoped the conference would be "most successful" in discussing the situation in Gaza. He called for lifting the Israeli blockade and for the two-state solution to be applied.

The UN chief emphasised the need for both sides to avoid violations of international law, and advised leaders to overcome their differences to put an end to the conflict.

He noted the destruction of Gaza's infrastructure, homes, UN facilities – which sheltered many Palestinians – and the killing of many UN employees during the latest Israeli offensive.

Ban concluded by calling for large donations to rebuild the destroyed enclave.

The conference is being attended by more than 30 foreign ministers under joint Egyptian-Norwegian leadership.

More than 50 national delegations and around 20 representatives from regional and international organisation are present. Palestinian President Mahmoud Abbas, US Secretary of State John Kerry, UN Secretary General Ban Ki-moon and EU foreign policy Chief Catherine Ashton are also in attendance.

A briefing will follow the conference to announce financial contributions to Gaza.

An Egyptian-brokered ceasefire between the Palestinian factions and Israel in late August ended a fifty-day Israeli assault on the Gaza Strip. Nearly 2,200 Palestinians were killed during the offensive, in addition to more than 12,000 injured. On the Israeli side, 73 were killed, mostly soldiers.

The Palestinian government has issued a 76-page document with a plan for Gaza's reconstruction. It calls for $4 billion to rebuild the enclave, with most of the amount devoted to building houses for roughly 100,000 homeless people.

Ahead of the international gathering, the Palestinian unity government arrived in Gaza on Thursday for a 24-hour visit, the first by a joint Hamas-Fattah delegation since the rival groups ended years-long tensions.

During a press conference held by the Palestinian premier on Thursday, Rami Al-Hamdallah, an independent political figure, asserted that "returning safe and normal life" to Gaza and "full unification between the occupied West Bank and East Jerusalem" represent the unity government's key priorities.

*This story was updated on 13 October.