At a stop in Kirkwood Tuesday morning, Romney took several shots at President Barack Obama, but did not mention any of his Republican challengers by name.
Romney was introduced in Kirkwood by former Republican Sen. Jim Talent. Also in the Romney entourage was State Auditor Tom Schweich, whose name is being floated as a possible Senate nominee to take on Sen. Claire McCaskill.
This is Romney's first visit to Missouri during this campaign.
After spending the early part of the day in the St. Louis suburbs, Romney was headed to the Kansas City area for a fundraiser at William Jewell College in Liberty.
The first of the Republican caucuses was scheduled for Tuesday night in Barry County in southwest Missouri. County caucuses are scheduled throughout the state through March 24, but most will take place this weekend.
The nominating contest are also drawing Ron Paul and Rick Santorum to the state. Paul will make a stop Thursday morning on the University of Missouri campus in Columbia. He'll host a "town hall" meeting at at the Carnahan Quadrangle on the University campus.
Santorum has been a regular visitor to Missouri before and since his victory in the state's primary in February. Santorum is scheduled to appear in Osage Beach Friday. He'll headline a rally at the Main Street Music Hall Theater from 10:30 a.m. to noon.
Newt Gingrich, who's name did not appear on the Missouri primary ballot is so far not scheduled to appear in the state before the weekend caucuses.