Condoleezza Rice, the US Secretary of State, is to visit the Middle East shortly in the wake of an optimistic prediction by Ariel Sharon that Israel and the Palestinians could be on the verge of a "historic breakthrough".
Ms Rice's visit to explore prospects for political progress was disclosed amid separate discussions on a possible tripartite mechanism to prevent isolated breaches ending the present undeclared truce.
The tentative plans have been discussed in a flurry of diplomatic activity which has included a visit by the US Assistant Secretary of State William Burns, who met Mr Sharon last night.
Dov Weisglass, Mr Sharon's most senior adviser, was on his way to Washington last night to brief senior US officials after the Israeli Prime Minister said he was "very satisfied" by the efforts of the new Palestinian President Mahmoud Abbas to call an end to militant violence.
Mr Sharon said in a speech last night: "I believe that the conditions are now ripe to allow us and the Palestinians to reach a historic breakthrough in the relations between us." He added that if the Palestinians acted in "a comprehensive fashion to fight terror, violence and incitement" Israel could return to the internationally agreed road-map to peace and co-ordinate with the Palestinians its planned withdrawal of 7,500 settlers from Gaza.
Using the Palestinian President's familiar name, Mr Sharon told the mass-circulation daily Yedhiot Ahronot: "There is no doubt Abu Mazen has started to work. I am very satisfied with what I am hearing is happening on the Palestinian side and I am very interested in advancing processes with him."
Israeli sources also confirmed last night that the army intended to halt targeted killing of militants provided the truce held on the Palestinian side. But the sources said that Israel reserved the right to continue to act against "ticking bombs" cases where it positively identified individuals preparing to attack an Israeli target.
One idea floated in informal talks involving Washington is that the US would help to co-ordinate with Israeli and Palestinian security officials some form of fast-track unit aimed at ensuring that any isolated incidents, whether attacks by militants or shootings and arrests by Israeli forces, do not escalate into wider violence.
The Palestinians blame Israel for the breakdown in the 2003 ceasefire brokered by Mr Abbas when he was prime minister by continued pursuit and assassinations of militants. While not endorsing this interpretation, a government source said: "Israel will not repeat its actions from the previous time."
Israel is reluctant to respond publicly to the call by the Palestinian leadership, repeated by Mr Abbas yesterday, for a formal agreement to the conditions set by the armed factions for a full and formal ceasefire on the grounds that it would "legitimise Hamas and Islamic Jihad". But the sources said that Israel was considering prisoner releases as a confidence-building measure.
The demand for militants to be released was a central condition in talks between Mr Abbas and the armed factions in Gaza over the weekend. What remains to be seen is whether Mr Sharon is prepared to sanction releases in sufficient numbers to give Mr Abbas the leverage he needs with the armed factions.
In a further symbol of Mr Abbas's determination to maintain law and order, the Palestinian leadership yesterday issued a decree banning people not in the security forces from carrying weapons. The decree, issued by Prime Minister Ahmed Qureia, emphasised crime rather than militant activity as a reason for the ban.
There were also unconfirmed indications that Nasser Yousef, who played a leading role in the crackdown on militants ordered by Yasser Arafat in the mid-1990s, would become Security Minister. General Yousef subsequently quarrelled with Arafat over the failure to reform the security services as Mr Abbas is now pledged to do.
There was some confusion over the pace of deployment of Palestinian security forces to southern Gaza after the Israeli military said it had already started. Palestinian sources, however, said it would start today after a delay caused by "technical difficulties".
There has been frequent combat in recent weeks in the southern town of Khan Yunis after mortar and rocket attacks, and a three-year-old girl was killed by Israeli fire to the north of it on Wednesday after two rockets were launched from the area.