Switzerland is to close consulates in Amsterdam, Las Palmas and Houston as part of cost cutting-measures, with three other closures to be announced later.
The foreign ministry announced cuts to the tune of SFR6.2 million ($4.72 million) earlier this year but gave no details at the time.
"The network abroad is not fixed in concrete. It must reflect the needs and the resources we have at our disposal," commented foreign ministry spokesman Jean-Philippe Jeannerat.
He said that as a result, the ministry did not issue a statement when every measure was announced.
The closures were made public in Saturday's edition of Zurich's Tages Anzeiger newspaper.
Jeannerat said Swiss citizens living in the regions concerned by the closures had been informed.
He added that the ministry would try to find a solution for staff affected by the decision in the Netherlands, Spain and the United States.
But "a small number" of local people would be made redundant.
Despite the economy measures, the foreign ministry continues to open new consulates. Switzerland is to open a representation next year in the Chinese city of Guangzhou, which is rapidly expanding.
The consulate in the British city of Manchester is to be transferred to the Scottish capital, Edinburgh.
Jeannerat explained that the ministry's decisions were based on three criteria – the number of Swiss living in a region, the demand for consular services and ministry finances.
swissinfo with agencies
Switzerland is closing its consulates in Amsterdam (The Netherlands), Houston (United States) and Las Palmas (Spain).
But it is next year opening a representation in the Chinese city of Guangzhou.
The consulate in the British city of Manchester is to be transferred to Edinburgh.
The main activity of Switzerland's consulates is helping Swiss abroad.
This includes, for example, issuing and renewing passports and answering questions about civil status (births, marriages and deaths).
It also involves aid to Swiss who might be passing through the region.
Consulates are also responsible for issuing visas.