US troops, who are supporting the Iraqi millitary, gather east of MosulIt will take “three months to eliminate”Isisin Iraq,according to the country’s Prime Minister, Haider al-Abadi.Backed by US forces, the Iraqi military has been battling to dislodge the militant group fromMosul, the largest city held by Isis in either Iraq or Syria and the de-facto capital of its self-styled Islamic caliphate.But more than two months into the operation, only a quarter of the city has been taken. Commanders have blamed the slower pace on the need to protect civilians who have mostly stayed intheir homes rather than fleeing as was expected.  Read moreWorshippers celebrate Christmas in a town finally liberated from IsisChristians in Mosul-area town liberated from Isis celebrate ChristmasMuslim businessman erects tallest Christmas tree in BaghdadIsis car bombs kill 23 people in recently liberated district of MosulMr Abadi previously said the city – around 250 miles north of the capital Baghdad – would be retaken by the end of the year. But with elite Iraqiforces entering a planned “operational refit” this month, he has been forced to revise his prediction.“Conditions indicate that Iraq needs three months to eliminate Daesh (Isis),” state TV quoted Mr Abadi as saying.The city has been held by the group since its fighters drove the Iraqi army out in June 2014.