A(n) ____________ and a(n) ____________ are two defining characteristics of an Intergovernmental Organisation.

Peacekeeping force, treaty
Treaty, agreement between two or more nations
Agreement between two or more nations, declaration
Agreement to work together on issues of common interests, peacekeeping force

Treaty, agreement between two or more nations

The correct answer is:

Treaty, agreement between two or more nations

The correct answer is "Agreement between two or more nations, declaration."

To arrive at this answer, we need to understand the key components of an Intergovernmental Organization (IGO).

An Intergovernmental Organization is an entity formed by the agreement between two or more nations to work together on issues of common interests. Therefore, the first characteristic is an "Agreement between two or more nations."

Additionally, as IGOs often have specific goals and objectives, they also typically have a declaration that outlines the purpose and principles of the organization. This declaration serves as a guiding document for the member nations, and it sets out the common goals and values that the organization aims to achieve.

Hence, the two defining characteristics of an Intergovernmental Organization are "Agreement between two or more nations" and "declaration."