On the basis of a referendum held on 21 May 2006, Montenegro declared independence from Serbia and Montenegro on 3 June 2006. In a letter dated on the same day, the President of Serbia informed the United Nations Secretary-General that the membership of Serbia and Montenegro in the UN was being continued by Serbia, following Montenegro's declaration of independence, in accordance with the Constitutional Charter of Serbia and Montenegro. Montenegro was admitted to the UN on 28 June 2006.