CAIRO  - UN leader Ban Ki-moon arrived in Cairo on Monday to bolster Egypt-mediated efforts for a ceasefire in Gaza which officials said could end the conflict before it worsens with a possible Israeli ground invasion.
Ban will inject heavyweight impetus into the peace effort, meeting Foreign Minister Mohammed Kamel Amr and Arab League chief Nabil al-Arabi before flying to see Israeli Prime Minister Benjamin Netanyahu and Palestinian chief Mahmud Abbas.
Egyptian mediators have been hosting marathon indirect talks between a Hamas team led by Khaled Meshaal and an Israeli envoy, which an Egyptian official said had produced "encouraging signs" on ending the crisis, now in its sixth day.
"The secretary general wishes to add his diplomatic weight to these efforts, which are considerable and extremely important," UN spokesman Martin Nesirky told reporters from Cairo on Ban's arrival.
Hamas leader Meshaal earlier told a news conference earlier his group would respect a ceasefire if Israel stopped its "aggression" on Gaza, but insisted the blockade of the impoverished and densely populated enclave must also end.
"We are not against a calming, but we want our demands... to end the thuggery, to end the aggression and to lift the blockade," he said.
Privately, a senior Hamas official said they were seeking only a "commitment" to ending the siege that Israel imposed when the Islamist movement seized Gaza from its secular Fatah rivals in 2007.
Another official close to the talks said both sides wanted assurances of a halt to military actions, including Hamas rocket fire and Israeli strikes such as that which killed Hamas's military chief on Wednesday, sparking the conflict. Other demands, such as ending the blockade, could be discussed after a preliminary ceasefire comes into force, he said.
An Egyptian official said the talks so far have been promising.
"We've received encouraging signals that it might be possible to stop the fighting and the bloodshed," which has so far cost the lives of more than 100 people, the official said. "I hope, that maybe by the end of the day, we receive a final signal of what may be achieved to stop hostilities."
Hamas's last sustained conflict with Israel in December 2008-January 2009 halted with an Egypt-mediated truce that was meant to guarantee a loosening of Israel's blockade of Gaza.
While, Russia on Monday accused the United States of seeking to "filibuster" a UN Security Council statement on the Gaza crisis and said it could propose a full resolution on the conflict. Russia's UN envoy Vitaly Churkin said one country on the 15-nation council indicated "quite transparently that they will not be prepared to go along with any reaction of the Security Council."