The Palestinians have decided to "turn the dark page of division for ever", President Mahmud Abbas said on Wednesday as he joined Hamas leader Khaled Meshaal at a Cairo reconciliation ceremony.
Representatives of a total of 13 Palestinian factions as well as independent political figures, inked a deal on Tuesday following talks with Egyptian officials.
It provides for the formation of an interim government of independents to lay the groundwork for presidential and parliamentary elections within a year.
The deal, which was announced last week, comes after 18 months of fruitless talks.
It has been welcomed by Palestinians in the divided territories -- demonstrations in support were planned in both the Gaza Strip and the West Bank which have ruled by rival administrations since Hamas ousted Abbas loyalists from Gaza in June 2007.
But Israel responded angrily, threatening to withhold the transfer of Palestinian tax revenues until it could be sure no money would go to Hamas.
Home front defence minister Matan Vilnai told Israeli public radio on Wednesday that Abbas had "made a mistake in agreeing this deal when Hamas is in a position of weakness, which explains why it made moves towards reconciliation."
The minister said Abbas should have insisted on a "clear declaration from Hamas on recognising Israel and condemning terrorism before signing."
Announcing Serry's attendance at the Cairo ceremony, UN chief Ban Ki Moon's spokesman Martin Nesirky said he "strongly" appealed to all the Palestinian factions to commit to the principles set for the Middle East process by the Quartet of major diplomatic players.
Those include the recognition of Isarael's right to exist.
"The secretary general has continually supported efforts for unity and the work of Egypt and President Abbas in this regard," Nesirky said.
"The secretary general therefore strongly appeals to all Palestinian parties to commit to these principles," he added.
But Abbas made clear on Tuesday that Hamas would not have to amend its charter to recognise Israel under the reconciliation deal.
"It is not required of Hamas to recognise Israel. We will form a government of technocrats and we will not ask Hamas to recognise Israel," he said.
Palestinian officials have said the new government's role will be to manage affairs in the Palestinian territories, while the Palestine Liberation Organisation, of which Hamas is not a member, will remain in charge of peace talks with Israel.
Among the first tasks to be tackled is the establishment of a higher security council tasked with examining ways to integrate Hamas and Fatah's rival security forces and create a "professional" security service.
The accord also calls for the creation of an electoral tribunal and for the release of a number prisoners held by the rival movements in jails in the West Bank and Gaza.
The reconciliation deal marks a diplomatic coup for Egypt's new government, 11 weeks after president Hosni Mubarak was toppled in a popular revolt.
Cairo had tried for more than a year to mediate between Fatah and Hamas but its efforts fell flat.
