Caught flat-footed by President Barack Obama on immigration last week, Romney promised a long-term solution to let young illegal immigrants stay in the United States, but offered only a few minor proposals.
Romney told a meeting of a national Hispanic group in Florida that he would "replace and supersede" Obama's executive order allowing hundreds of thousands of immigrants brought to the country illegally by their parents to avoid being sent home.
"Some people have asked if I will let stand the president's executive action. The answer is that I will put in place my own long-term solution that will replace and supersede the president's temporary measure," Romney told the National Association of Latino Elected and Appointed Officials.
But he did not say whether he would repeal the order if elected president on November 6 and was greeted with tepid applause and a few scattered boos.
It was Romney's first address to a major Latino group since May, when he surprised many by avoiding the topic of immigration and talking instead about education.
Former Republican presidential rival Herman Cain took the rhetoric against illegal immigrants further when he joked about setting up an electrified fence in the border with Mexico.
Obama's announcement on immigration last week put Romney on the defensive just as the Republican was rising in the polls and enjoying his best few weeks of the campaign.
It also effectively killed off a plan for a similar immigration proposal by U.S. Senator Marco Rubio of Florida, a Cuban-American who is being vetted as a possible Romney vice presidential pick.