Donald Trump has questioned the effectiveness of the United Nations, saying it's just a club for people to “have a good time”.

The statement came days after the UN Security Council voted to condemn Israeli settlements in the West Bank and east Jerusalem.

The president-elect wrote Monday on Twitter that the UN has “such great potential,” but it has become “just a club for people to get together, talk and have a good time. So sad!”

On Friday, Trump warned, “As to the UN, things will be different after Jan 20th,” referring to the day he takes office.

The decision by the Obama administration to abstain from Friday's UN vote brushed aside Trump's demands that the US exercise its veto and provided a climax to years of icy relations with Israel's leadership.

Trump told The Associated Press last December that he wanted to be “very neutral” on Israel-Palestinian issues. But his tone became decidedly more pro-Israel as the presidential campaign progressed. He has spoken disparagingly of Palestinians, saying they have been “taken over” by or are condoning militant groups.

Trump's tweet Monday about the UN ignores much of the work that goes on in the 193-member global organisation.

This year the UN Security Council has approved over 70 legally binding resolutions, including new sanctions on North Korea and measures tackling conflicts and authorising the UN's far-flung peacekeeping operations around the world.

The General Assembly has also approved dozens of resolutions on issues, like the role of diamonds in fuelling conflicts; condemned human rights abuses in Iran and North Korea; and authorised an investigation of alleged war crimes in Syria.