The United Nations General Assembly has agreed to allocate $18 million (CHF16 million) to proceed with the detailed planning of urgently needed repairs of its European headquarters in Geneva, the Palais des Nations.
The renovation project, known as the Strategic Heritage Plan, includes the demolition and replacement of one of its extensions.
Swiss UN ambassador Paul Seger told the Swiss News Agency that the decision to allocate the money means that the detailed planning phase, scheduled for the next two years, can now go ahead.
The UN Secretary General is to present the General Assembly with an updated estimate of the costs involved In autumn 2015, and at that point the UN will have to decide about the entire budget.
The initial estimate of the cost was at least CHF618 million.
Switzerland is paying for work which is already underway at the building, the main part of which dates back to 1937: replacement windows, improved insulation, modernisation of the lighting and ventilation and installation of solar panels.
In June 2013 Foreign Minister Didier Burkhalter announced that Switzerland would meet 50% of the total repair bill, after the cabinet adopted a new strategy to boost the attractiveness of International Geneva in the face of ever tougher competition from other cities to house international organisations.