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:
John Kasich through his career
Mitt Romney to campaign with John Kasich in Ohio
MT. PLEASANT, SC - FEBRUARY 10: Republican presidential candidate John Kasich talks to an overflow crowd outside of Finn's Brick Oven Pizza February 10, 2016 in Mt. Pleasant, South Carolina. The South Carolina Republican primary will be held Saturday, February 20. (Photo by Sean Rayford/Getty Images)
11/3/95 - Rep. John R. Kasich (R-OH), seated 2nd from left, and Sen. Pete V. Domenici (R-NM) in the dark suit standing, go over their response to President Clinton's radio address just prior to recording the radio broadcast in the Senate studio. Kasich was casually dressed as the House was out of session for the weekend. (Photo by Robert A. Reeder/The Washington Post/Getty Images)
D:\BOB\budget3.tif - slug: NA/BUDGET date: May 2, 1997 photog: Robert A. Reeder TWP The Rotunda of the Capitol description: GOP happy with their signed budget John R. Kasich (R-OH) is having a particularly good time during the GOP announcement of a new budget in the Rotunda of the Capitol. In front of him is Speaker Newt Gingrich. (Photo by Robert A. Reeder/The Washington Post/Getty Images)
P 350430 022 2May99 Manchester, Nh John Kasich (R-Oh), At The First-In-The-Nation Primary Kick-Off Weekend. (Photo By Jonathan Elderfield/Getty Images)
UNITED STATES - FEBRUARY 02: HOUSE ARMED SERVICES--John R. Kasich, R-Ohio, and Duncan Hunter, R-Calif., talk during House Armed Services Committee hearing on the president's fiscal year 2000 defence budget authorization budget request. (Photo by Douglas Graham/Congressional Quarterly/Getty Images)
Former Ohio congressman John Kasich attends the Republican National Convention at the Xcel Energy Center in St. Paul, Minnesota, Wednesday, September 3, 2008. (Photo by Harry E. Walker/MCT/MCT via Getty Images)
WASHINGTON, DC- Dec. 01: Governor-elect John Kasich, R-Ohio, and House Minority Leader John A. Boehner, R-Ohio, during a news conference after their meeting with other Republican members and governors-elect. Boehner is the presumed House Speaker for the 112th Congress. (Photo by Scott J. Ferrell/Congressional Quarterly/Getty Images)
John Kasich, governor of Ohio, speaks during a groundbreaking ceremony for the Cleveland Medical Mart and Convention Center in Cleveland, Ohio, U.S., on Friday, Jan. 14, 2011. The Cleveland Medical Mart and Convention Center will include a 100,000 square foot medical mart and an adjoining convention center with 230,000 square feet of exhibit hall space. The facility is expected to open in September 2013. Photographer: David Maxwell/Bloomberg via Getty Images
COLUMBUS, OH - MARCH 30: Ohio Governor John Kasich works long hours with staff on his new budget proposal at his office, in the Ohio State House office, Columbus, Ohio, Wednesday, March 30, 2011. Newly elected republican Ohio Governor John Kasich is working toward to balancing an Ohio budget in deficit through a budget proposal with extensive budget cuts, spending reform, and changes in labor laws, including restrictions on collective bargaining. (Photo by Melina Mara/ The Washington Post via Getty Images)
US Republican presidential candidate and former Massachusetts Governor Mitt Romney (2nd L) waves alongside Ohio Republican Senator Rob Portman (L) and Ohio Governor John Kasich (R) during a campaign stop at Tom's Ice Cream Bowl in Zanesville, Ohio, on August 14, 2012. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP/GettyImages)
UNITED STATES - AUGUST 28: Ohio Gov. John Kasich speaks at the 2012 Republican National Convention at the Tampa Bay Times Forum. (Photo By Chris Maddaloni/CQ Roll Call)
COLUMBUS, OHIO - JULY 21: Ohio Governor John Kasich gives his speech announcing his 2016 Presidential candidacy at the Ohio Student Union, at The Ohio State University on July 21, 2015 in Columbus, Ohio. Kasich became the 16th candidate to officially enter the race for the Republican presidential nomination. (Photo by Ty Wright/Getty Images)
CONCORD, NH - FEBRUARY 09: Republican presidential candidate Ohio Governor John Kasich waves to the crowd after speaking at a campaign gathering with supporters upon placing second place in the New Hampshire republican primary on February 9, 2016 in Concord, New Hampshire. Kasich lost the Republican primary to Donald Trump, though he upset fellow Republican governors Chris Christie and former Governor Jeb Bush. (Photo by Andrew Burton/Getty Images)
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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:
John Kasich on the campaign trail
Mitt Romney to campaign with John Kasich in Ohio
MILFORD, NH - SEPTEMBER 7: Republican presidential candidate John Kasich greets supporters at the Labor Day parade on September 7, 2015 in Milford, New Hampshire. Kasich, buoyed by what observers called a strong performance in the first GOP debate, has emerged as a first tier presidential candidate with voters in New Hampshire, the nation's first primary state. (Photo by Kayana Szymczak/Getty Images)