Palestinian President Mahmoud Abbas said he would demand full membership of the United Nations when he goes to the UN General Assembly next week, setting up a diplomatic clash with Israel and the United States.

'We are going to the UN to request our legitimate right, obtaining full membership for Palestine in this organisation,' Abbas said in a televised speech on Friday.

'We are going to the Security Council,' he added, to rapturous applause from his audience of Palestinian leaders. 'As for other options, we have not yet taken a decision on them,' he said.

Both Israel and the United States are firmly opposed to such a move, arguing that a Palestinian state can only be created through direct negotiations.

Washington has already said it will veto any statehood resolution in the Security Council and some U.S. politicians have said they will try to cut American aid to the Palestinians, totalling some $500 million a year, if they refuse to back down.

If the United States does veto the resolution, the Palestinians could then go to the full UN General Assembly. It does not have the power to grant the Palestinians membership, but could recognise it as a non-member state.

Such a move would give the Palestinians possible access to other international bodies, including the International Criminal Court, from where it could seek to sue Israel for the longstanding occupation of the West Bank.

Abbas said he wanted to see a Palestinian state recognised on the basis of the 1967 lines, comprising the West Bank, East Jerusalem and the Gaza Strip, adding that this would then enable the Palestinians to return to negotiations with Israel.

He stressed that any popular protests in support of his initiative should be peaceful. Israel fears that the UN showdown could spark violence across the West Bank and is putting its forces on high alert in the area.

Abbas is due to address the UN General Assembly on September 23, when he said he would present Palestine's membership bid.-Reuters