The United States on Thursday spoiled a long-shot Palestinian bid for full United Nations membership, vetoing a Security Council measure despite growing international distress over the humanitarian crisis in Gaza.

The move by Israel's key ally had been expected ahead of the vote, taking place more than six months into Israel's military offensive in the besieged Palestinian territory, in retaliation for the deadly 7 October attack by Hamas militants on southern Israel.

Twelve countries voted in favor of the draft resolution recommending full Palestinian membership. Britain and Switzerland abstained.

Palestinian leader Mahmud Abbas's office called the US veto "a blatant aggression... which pushes the region ever further to the edge of the abyss."

"The fact that this resolution did not pass will not break our will, and it will not defeat our determination," Palestinian Ambassador to the UN Riyad Mansour said, in tears.

"We will not stop in our effort. The state of Palestine is inevitable. It is real.

"Please remember that once this session adjourns, in Palestine there are innocents paying the price with their lives... for the delay in justice, freedom and peace," he added, as others in the room also cried.