Mitt Romney will campaign with John Kasich Monday at two stops in Ohio, NBC News has learned from a source familiar with the plans.
Romney is not expected to endorse the Ohio governor during the campaign swing, the source said, but it will be the first time Romney has campaigned on behalf of a Republican candidate this cycle.
It's a significant move for the former Republican nominee, who previously recorded campaign telephone "robocalls" for Kasich as well as Marco Rubio.
See more of Kasich through his career:
Earlier this month, at a speech in Utah, Romney lambasted frontrunner Donald Trump as a "fraud" and warned of the dangers to the Republican Party if Trump were the nominee.
"I believe with all my heart and soul that we face another time for choosing," said Romney at the time, "one that will have profound consequences for the Republican party and more importantly, for the country."
Romney is expected to appear with Kasich at his events in Canton and outside Columbus Monday afternoon. The trips come one day before the crucial Ohio primary, a must-win for Kasich, as Trump ups his attacks on the sitting governor.
Kasich is scheduled to make three stops in Utah on Friday - in Orem, Salt Lake City, and Kaysville. Utah's primary is on March 22.
See more of Kasich on the campaign trail: