Your company based in the United States imports goods in Belgium where they are temporarily stocked (importation of goods in Belgium). The goods are sold to various EU companies located all around Europe afterwards.
Your company, acting as the importer of the goods, should normally be VAT registered through a VAT representative in Belgium (where the goods are put into free circulation) and pay Belgian VAT immediately (cash payment: VAT on importation is paid to customs authorities at the border where the goods enter the European Union).
Member States determine the conditions under which the imported goods should be introduced into their territory. They prescribe the process to declare the importation of goods towards the Authorities. Member States may allow for the VAT to be paid subsequently in a periodic VAT return. This declaration will include both the VAT due and the deductible VAT (postponed accounting via VAT return). A payment delay may also be authorized (deferred payment).
Belgium implemented both solution: postponed accounting via VAT return (licence ET 14.000) and deferred payment.