DENVER, Colorado — Mitt Romney would not deport young illegal immigrants permitted to stay in the United States under an order issued by President Barack Obama, the Republican White House hopeful said in Tuesday's Denver Post.

"The people who have received the special visa that the president has put in place, which is a two-year visa, should expect that the visa would continue to be valid. I'm not going to take something that they've purchased," Romney said.

The candidate's comments in the political battleground of Colorado, seen as a critical state for Romney now that his path to election victory is narrowing, suggest a pivot away from his firm opposition to Obama's executive order.

On June 15, the president suspended the threat of deportation against hundreds of thousands of law-abiding immigrants who were brought to the country as minors, delighting crucial Hispanic voters ahead of the November 6 election.

The scheme applies to people brought to the United States before the age of 16, who are currently under 30, are in school or have graduated from high school, or have served in the military and have not been convicted of a felony.

The affected youths will be able to apply for work permits, but not be granted permanent residence or put on a path towards citizenship. The move offers a two-year deferment of deportation proceedings that could be extended by a further two years on expiry.

Obama's decision will go some way to enshrining the goals of the DREAM Act, legislation backed by the White House that could lead to young illegal immigrants gaining permanent residency.

The Republican nominee has had trouble connecting with Latinos, who now make up the largest ethnic minority voting demographic in the country, and he has promised to veto the DREAM Act if it passed during a Romney presidency.

Romney has stressed the need for a more comprehensive solution to America's immigration problem, and suggested to the Denver Post that immigration would be an early issue to tackle if he is elected in November.

"Before those visas have expired we will have the full immigration reform plan that I've proposed," he said.

Romney has previously said he would provide a path to citizenship for immigrants who are students and serve in the US military.

"The president promised in his first year, his highest priority, that he would reform immigration and he didn't. And I will."

Obama's re-election campaign said Romney's "latest immigration pivot raises more questions than it answers.

"He still has not said whether he would continue the administration's policy that provides a temporary reprieve from deportation for young people who were brought here through no fault of their own," Obama's director of Hispanic press Gabriela Domenzain said in a statement.

"Would he side with his extreme anti-immigration advisors and repeal this measure?" she asked. "Would he deport those who have received a deferment when the program expires after two years?"

Congress and Obama have failed to reach a deal to pass reform that would bring more than 11 million illegal immigrants out of the shadows.