IE 11 is not supported. For an optimal experience visit our site on another browser.

Iraqi forces backed by US troops attack ISIS stronghold to liberate Mosul

01:41

Backed by the U.S., Iraqi forces launched a massive offensive overnight to wrestle control of Mosul, the country’s second-largest city, from the hands of ISIS. The attack is the largest ever operation against the terror group. NBC’s chief foreign correspondent Richard Engel reports for TODAY from northern Iraq.