Mitt Romney will announce on Thursday his bid for Utah's up-for-grabs U.S. Senate seat, sources close to the 2012 Republican presidential nominee told NBC News.

The announcement will be in a video message rather than a large-scale rally or kick-off event, according to NBC. Romney's first live campaign speech will be given at the Utah County Lincoln Day dinner on Friday night, sources told NBC.

In a Feb. 1 tweet, Romney said he would make an announcement about the Utah race by late this week. He did not specify at the time whether he would be vying for the seat — but a link to mittromney.com included in the tweet invites visitors to "Join Team Mitt."

Romney tweet Feb. 1

Romney will be campaigning for the seat soon to be vacated by 83-year-old retiring Republican Sen. Orrin Hatch.

Romney, the 70-year-old former governor of Massachusetts, has long been rumored to want the seat. Romney, a practicing Mormon, is heavily favored in Utah, a strongly Republican state with a large and influential Mormon population.

During the 2016 presidential campaign, Romney spoke out openly against then-candidate Donald Trump. In a March 3, 2016, speech, Romney called Trump a "phony," a "fraud" and a "con artist" who would erode conservative values.