Why is Portuguese still not an official language of UN?

There are a few factors that help explain why Portuguese is still not an official language of the United Nations:

• Prestige and geopolitics – The six official UN languages (English, French, Spanish, Russian, Chinese, Arabic) belong to nations that were influential when the UN was founded or that have gained global stature since. Portugal and Brazil wield less geopolitical and economic clout.
• Number of speakers – With around 260 million native speakers worldwide, Portuguese ranks behind the six official UN languages in total speakers. This reduces pressure to elevate its status.
• Concentration of speakers – Most Portuguese speakers are located in Portugal and Brazil. The language has less global reach than more widely dispersed languages like English or French.
• Cost – Adding another official UN language incurs significant expense for translation and interpretation services. With a constrained budget, the UN is unlikely to expand the number of official languages without major pressure.
• Representation – The Community of Portuguese Language Countries (CPLP) gives Portuguese some voice as an unofficial language in UN forums and agencies like UNESCO already. This reduces the urgency for official designation.

So while Portuguese has risen as a global language, it still lacks the geopolitical sway or international reach to compel the UN to add it as an official language at present. However, advocacy by Portugal, Brazil and other CPLP nations continues.