Yes, that is a very difficult position for white to win.

Black has a fortress coupled with the fact that white can't queen a pawn is enough to force the draw.  Pawns are something like the life blood of an endgame.  This material imbalance in a middlegame for example may get black mated, but in an endgame you need to be able to queen.  White doesn't have enough pawns = can't win :)

By which I mean, this is how you would know to aim for this in the middlegame where you have to give up your queen.  You may think oh crap I'll definitely lose, but actually only black had winning chances here... if his king had a little more cover it's white who may have to resign.