The two prime ministers would meet "at the beginning of next week before Mahmud Abbas' trip to Washington", where he is due to hold talks with US President George W. Bush on July 25, a senior Israeli official told AFP.

A meeting scheduled for last Wednesday was called off after a row broke out between Abbas and Palestinian leader Yasser Arafat, centred around Abbas's failure so far to persuade Israel to release more than 350 of the estimated 6,000 Palestinians in its jails.

But Israeli army radio reported Thursday that Sharon would show "flexibility" on the prisoners issue and sanction the freeing of "administrative detainees" who belong to the radical Islamic groups Hamas and Islamic Jihad who have not been implicated in the killings of Israelis.

Abbas accepted late Wednesday an invitation to meet US President George W. Bush in Washington in a move designed to give momentum to the troubled peace process and which is bound to boost the Palestinian prime minister's profile on the world stage.

Talks are expected to focus on the US-backed roadmap for peace which aims to create an independent Palestinian state by 2005, his office said in a statement Wednesday night.

"This visit will be centred on the commitments made by Israel to freeze settlements in the progress in the peace process," said the statement.

Palestinian foreign minister Nabil Shaath, minister of state for security affairs Mohammad Dahlan, parliament speaker Ahmad Qorei and finance minister Salam Fayad are all due to travel with Abbas to Washington.

It was thought that Abbas could not risk further damage to his poor popularity ratings by travelling to the United States while Palestinian leader Yasser Arafat remains trapped in his Ramallah office by the Israeli army.

But Palestinian negotiator and MP Saeb Erakat announced Wednesday that Arafat, who recently healed a rift with his prime minister, had approved the trip.

"President Arafat gave Abu Mazen his complete blessing," Erakat told AFP, using Abbas' nom-de-guerre.

Arafat's unexpected green light came as Sharon wrapped up a European tour to convince foreign diplomats to boycott the veteran leader, whom Israel accuses of being the main obstacle to peace by undermining Abbas' position and abetting violence.

But he failed to convince his Norwegian counterpart Kjell Magne Bondevik to sever ties with Arafat, his second rebuff in days after receiving a similar response from British officials on the previous leg of his trip.

Abbas' visit nevertheless raised hopes that the roadmap for peace -- which is aimed at ending the violence and creating a Palestinian state by 2005 -- will gather momentum in coming days.

The radical Palestinian groups Hamas and Islamic Jihad criticised Prime Minister Mahmud Abbas' decision to travel to Washington for talks with US President George W. Bush.

Leaders of the two organisations, which are currently observing a freeze on anti-Israeli attacks, said that Abbas (also known as Abu Mazen) should not have agreed to travel to the States for his first official visit while Palestinian leader Yasser Arafat was still confined to his Ramallah headquarters.

They also said Abbas must resist any pressure from Washington to dismantle their organisations or confiscate their weapons.

"We demand that he does not comply or respond to the American pressure," the political leader of Hamas, Abdul Aziz al-Rantissi, told AFP.

Rantissi said that any attempt by the Palestinian Authority to dismantle his organisation or seize its weapons was doomed to failure like previous attempts by "the Zionist enemy... during the occupation".

Both organisations warned on Sunday that their truce could be called off if the Palestinian Authority tried to confiscate their weapons.

Mohammed al-Hindi, a leader of Islamic Jihad, also criticised the July 25 trip and said that any pledges of funds secured by Abbas should be regarded as an unacceptable "bribe to stop the intifida", the Palestinian uprising.

"He is going to listen to people like (US National Security Adviser) Condoleezza Rice, (Secretary of State) Colin Powell and George Bush who will demand the dismantling of the Palestinian organisations and the confiscation of weapons," he told AFP.