Abbas accused Hamas of carrying out killings against his security forces "unprecedented" in Palestinian history and plotting its takeover at the behest of foreign powers.

He said the Islamists had given Israel an "excuse to punish an entire people" and even accused the group with which he uneasily shared power for 15 months of having plotted to kill him.

"It was a premeditated plan agreed between Hamas leaders in Gaza and abroad, with foreign elements from the region," he said of the Islamists' seizure of control in the territory last Friday after a week of ferocious fighting.

"No dialogue with putschists, murderers and terrorists," he thundered in an address to a meeting of the Palestine Liberation Organisation, of which he is chairman but of which Hamas is not a member.

Abbas strongly defended his decision to dismiss the Hamas-led national unity government last Thursday and swear in an emergency cabinet at the weekend that Hamas has dismissed as an illegitimate lackey of Israel and the United States.

"Our main objective is to prevent the chaos from spreading to the West Bank," he said, adding that the new government of technocrats led by US-educated prime minister Salam Fayyad was the "clear answer to the coup."

Israel has seized on the formation of the new government in the West Bank -- the first without Hamas representation since the Islamists routed Abbas's secular Fatah faction in parliamentary elections early last year -- as an historic opportunity to relaunch the peace process.

Israeli Foreign Tzipi Livni telephoned Fayyad Wednesday to open dialogue with his government after the 15-month hiatus while the Islamists of Hamas -- blacklisted as a terror group by Israel and the West -- were in power.

The European Union, which like the United States, said it would resume direct aid to the Palestinian Authority, said Wednesday it was making its first transfer of 22 million euros (29.5 million dollars).

Abbas called for an international conference to be convened to oversee the relaunch of the moribund peace process, like the Madrid conference of 1991 that helped pave the way for the secret talks that led to the 1993 Oslo accords.

"We call for negotiations to resume ... and in the framework an international conference the details of which we will agree" with the Israelis, he said.

A meeting of the top diplomats of the Middle East peace Quartet -- US Secretary of State Condoleezza Rice, Russian Foreign Minister Sergei Lavrov, UN chief Ban Ki-moon and EU envoy Javier Solana -- set for June 26-27 in Egypt was reportedly called off because of the crisis stemming from Hamas' bloody takeover of Gaza.