The United States, United Nations, European Union and Russia (known as the Middle East quartet) warned at talks in London on Monday that payments could be slashed if the winner of last week's general election did not radically alter its principles before entering government.

The victory of the radical Islamist movement, behind dozens of suicide attacks in a five-year uprising, has already led Israel to warn that it will have no dealings with a Palestinian Authority which includes "terrorists" and to sit on customs revenues that it should hand over.

Hamas has made clear that its embrace of democracy will not lead it to give up its "right to resist Israeli occupation", even though it has not carried out any attacks for more than a year.

"The international aid which is offered to our people is a humanitarian need for the Palestinian people who are still living under Israeli occupation," Ismail Haniya, who led the list of Hamas candidates in last week's election, told AFP.

"This aid should not be linked to unfair conditions," he added.

While funding would continue for the time being, the quartet said "it was inevitable that future assistance to any new government would be reviewed by donors against that government's commitment to the principles of nonviolence, recognition of Israel, and acceptance of previous agreements and obligations."

Hamas's overall leader, the Damascus-based Khaled Meshaal, said the attempts by the West to force change on Hamas were doomed to failure.

"Our message to the US and EU governments is this: your attempt to force us to give up our principles or our struggle is in vain," Meshaal wrote in Britain's Guardian newspaper.