Did you have the attack of the rebels on Minsk Harbour yet? If not, try to go there. That attack doesn't start with a dialog with Mike, but automatically when you enter Minsk from the worldmap (not by ship or teleport) once you have all requirements.
Or are you missing the burning note that can be found a little bit down and right from the main plaza of Kagabangui? (Where the teleport stone plate is)