The amount is 5% ($286m) below the budget for the current two-year period (2016-17) and $193m below the proposal made by UN secretary general António Guterres in October last year.

In approving the budget on Sunday 24 December, the assembly also endorsed the move from a biennial planning and budgeting period to annual programme budget on a trial basis, as of 2020.

A note issued by the spokesperson for the secretary general on Tuesday 26 December said: “This signals one of the most significant shifts in the programme planning and budgeting process of the organisation since the 1970s.”

Johannes Huisman, the director of programme planning and budget, said most of the cuts in the new budget were under operating or “non-post” areas, such as information technology or travel.

The budget covers UN activities across a range of areas, including political affairs, international justice and law, regional cooperation for development, human rights and humanitarian affairs, and public information.

Huisman also said some reductions applied to personnel and paying for UN delegations to be posted internationally.

He added: “This is a reassurance we can give to the tax-payers that no stone will be left unturned to make sure that the money is spent properly and ultimately benefits the world community in the areas where the UN is needed.”