libgdx - How to resize a Tilemap according to aspect ratio

How can I resize my TiledMap so i can have it stretched correctly to the screen sizes of devices with different aspect ratio’s?

I’m looking for a way to be able to stretch X & Y direction seperately.

So something like using the TiledMapRenderer’s unitscale isn’t sufficient. (like mentioned here f.e.:
http://badlogicgames.com/forum/viewtopic.php?f=11&t=11584)

Been googling around but can’t find any examples

When i create my camera this is what my code looks like :

	cam = new OrthographicCamera(V_WIDTH, V_HEIGHT );
		cam.position.set((V_WIDTH / 3.55f), (V_HEIGHT / 2f), 0); // my map doesnt cover whole screen that's why ../ 3.55f


And I load my map with the tmxMapLoader & pass it to the tilemaprenderer like this:

	tilemaprenderer = new OrthogonalTiledMapRenderer(map)
		tilemaprenderer.setView(cam);