See ESC right:

Self-determination

Relevant ICESCR Articles:

01(1): All peoples have the right of self-determination. By virtue of that right they freely determine their political status and freely pursue their economic, social and cultural development.

01(3): The States Parties to the present Covenant, including those having responsibility for the administration of Non-Self-Governing and Trust Territories, shall promote the realization of the right of self-determination, and shall respect that right, in conformity with the provisions of the Charter of the United Nations.

Related Documents:

Declaration on the Granting of Independence to Colonial Countries and Peoples