Iraqi military forces flew the national flag above the main government complex in Ramadi earlier in the day, declaring they had recaptured the city, a provincial capital west of Baghdad, which fell to ISIL in May.
"2016 will be the year of the big and final victory, when Daesh's presence in Iraq will be terminated," Abadi said in a speech broadcast on state television, using an Arabic acronym for the ISIL terrorist group, also known as ISIS.
"We are coming to liberate Mosul and it will be the fatal and final blow to Daesh," he added.
Mosul, northern Iraq's main city, is by far the largest population center in the self-proclaimed caliphate that ISIL rules in Iraq and Syria, Reuters reported.
Gunshots and an explosion could be heard as a state TV reporter interviewed soldiers celebrating the victory with their automatic weapons held in the air.
The ISIL terrorists consider all Shiite Muslims and even Sunnis to be apostates. They swept through northern and western Iraq in June 2014 and declared a "caliphate" to rule over all Muslims from territory in both Iraq and Syria, carrying out mass killings and wreaking havoc on cities.