Mitt Romney will campaign with John Kasich Monday in Ohio, NBC News has learned from a source familiar with the plans.
Romney is not expected to endorse the Ohio governor, the source said, but it will be the first time Romney has campaigned for 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.
Earlier this month, Romney criticized frontrunner Donald Trump as a "fraud" and warned of the dangers to the party if the front-runner were to become the nominee.