See Number of ISIS Left in Mosul Close to Original Levels at Start of Campaign (dated December 12, 2016). Note that Defense Secretary Ashton Carter is trying to put a good face on what's happening:
Defense officials confirmed that the Islamic State has been pumping reinforcements into Mosul during the battle that was launched in mid-October, but said the maintained level of militants there doesn't indicate a stalemate....Trying to preserve Obama's "foreign policy legacy," which declared that the war in Iraq is over. Clearly, it is not.
Various members of the Obama Administration and their fellow Dems are carrying Obama's water with regard to other issues as well.
How this water-carrying really is:

