The so-called quartet, which also includes the European Union, Russia and the United Nations, tempered its criticism of Israel with an appeal to the Palestinian leadership to do more to halt "acts of terrorism" against Israelis.

But the rare criticism drew a dismissive response from Israel, which accused the quartet of hypocrisy.

"The quartet expresses its deep concern over Israeli military actions that result in the killing of innocent Palestinian and other civilians," the quartet said in its statement that was read by UN chief Kofi Annan.

"Such actions do not enhance security and undermine trust and prospects for cooperation."

US Secretary of State Colin Powell, who joined Annan at the talks with Russian Foreign Minister Igor Ivanov, top EU diplomat Javier Solana and Greek Foreign Minister George Papandreou, hammered home the point, explicitly criticising Israel's killing of a Palestinian militant leader on Saturday.

"I regret that once again we had an incident that could be an impediment to progress," he said, repeating Washington's stance that such moves were only appropriate if Israel knew the target was planning an imminent attack.

"We can understand the situation of quote 'a ticking bomb' when there is an immediate threat that needs to be dealt with," he said.

"But anything that is sort of out of that immediate definition has to be looked at in light of the consequences it will have to our ability to move forward," Powell said.

"It is a matter of concern," he said. "Having said that, it is important for us to remain committed to moving forward and to remind the parties of the obligations they entered into in Aqaba."

Powell was referring to a June 4 summit at which Israeli Prime Minister Ariel Sharon and Palestinian premier Mahmud Abbas vowed to follow the steps set down by the roadmap towards establishment of a Palestinian state by 2005.

"We cannot allow ourselves to be stopped or allow this process to come to an end because of these incidents," he said. "We have to keep moving forward."

But the quartet also had choice words for the Palestinians in its joint statement, coming at the ending of their first meeting at the principals' level in six months.

"All Palestinian individuals and groups must end acts of terror against all Israelis, anywhere," the quartet said.

"The quartet calls on the Palestinian authorities to take all possible steps to halt immediately the activities of individuals and groups planning and conducting attacks on Israelis."

Israel, meanwhile, reacted angrily to the criticism of its operation against Abdullah Qawasmeh, a local leader of the radical Islamic group Hamas.

"We reject these criticisms because the quartet, and in particular the Europeans, should know that terrorism also kills innocent people on the Israeli side," an Israeli official told AFP.

"They should rather pressure (Yasser Arafat's) Palestinian Authority to make the decision to fight terrorism."

The Palestinians seized on the Israeli response as evidence it was not serious about working with the quartet in implementing the long-awaited peace roadmap.

The Israeli reaction was a "sign that Israel does not want to implement the roadmap," said top Arafat aide, Nabil Abu Rudeina.

"Israel is running away from carrying out the plan and the quartet must exert pressure so that it will implement it without any modification and dispatch international observers to guarantee this," he said.

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