Hetzij ... hetzij ... - Either ... or ...

The construction hetzij ...hetzij ... is used in formal language to establish an emphatic contrast between two or more alternatives. This has the same effect as the construction 'either ... or ...' in English:

De voorzitter roept de Raad bijeen, hetzij op eigen initiatief, hetzij als gevolg van schriftelijke aanvraag van ten minste drie leden van de Raad.

The chair will summon the Council, either on his (her) own initiative, or as a result of a written request by at least three members of the Council.