2D Start Background fill the screen

Hi, I'm making a iOS/Android game and I have a start image before the game loads and the start menu background but I want it too fill the screen as at the moment there is still some background.

Heres what I'm talking about in images

As you can see the image is not filling the screen as I want it to do in the game.

If anyone can give me any assistance with how to make it fill the screen it would be most appreciated

Oh and quick note, I do want it primarily vertical as a rectangle and not completely square. Best regards, Luke