What Tony said is true in many countries that are not very open to the gospel.
While missionaries do some "pastoral" duties... the focus and even the training can be a little different. In the seminary that I attended, there was a special "missions" concentration for those who wanted to go on to the missions field after finishing up their M.Div.
As a missionary, while you may technically be their pastor, your aim is never to stay there. The reason is that in missions, the missionaries are not from the culture they are trying to reach (if they were, it would be evangelism). No matter how much you eventually fit in and are accepted, the missionary is always trying to build up native leaders that will be able to take over the ministry. Until the gospel is truely contextualized into that particular culture/community, the gospel will not really be rooted and/or spread. The best people that connect with the culture are people within the culture. (This is something that they should teach you in a missions-anthropology class)
In an ideal world, when the people the missionary is ministering to truely embrace and own the gospel, then the missionary can move on to another missions field - leaving the ministry in the hands of nationals.
Talk this over with your pastor and see if the church supports any missionaries that you can talk to.
Keep pressing on!