I should reiterate that the limit of two terms is because the people of these countries have asked for that limit. In the particular case of Burundi, it was to ensure there was appropriate power sharing among the parties in power. If the people of the particular country decide they are okay with three-year term limits, the international community would not oppose, if it's done in a democratic way.
On September 22nd, 2016. See this statement in context.