President Barack Obama unveiled a major, election-year policy shift on Friday that will allow hundreds of thousands of young immigrants brought into the country illegally as children to remain and work in the United States.

About 800,000 people who arrived before they turned 16 will not be deported and will be able to apply for work permits. Both changes track legislation stalled in Congress known as the DREAM Act — though, unlike that proposal, Obama’s executive order is temporary and will not provide a path to U.S. residency or citizenship.

“These are young people who studied in our schools,” Obama said from the White House Rose Garden. “They play in our neighborhoods. They’re friends with our kids. They pledge allegiance to our flag. They’re Americans in their heart, in their minds, in every single way, but one: on paper.”

His remarks were met with excited chatter and tears of joy by several undocumented students and their supporters holding American flags who gathered at the student life building at Miami Dade College’s Wolfson Campus in downtown Miami to watch the announcement.

Among them was José Machado, a 17-year-old rising senior at Miami Senior High School who arrived from Nicaragua when he was 6 because he and his twin brother needed a medical procedure. His family never went back.

His mother was deported last year after she was stopped for driving without a license. She was held in a detention center at first, and because he had no legal identification himself, José could not see his mother before she was sent back to Nicaragua.

“The policy change gives me an opportunity,” said José, who wants to go to college to study political science. “I know my mom will be proud now that I can move forward.”

The new protections, which take effect immediately, will apply to people 30 or younger who have lived in the United States for at least five years. They cannot have major criminal records and must be enrolled in school or have U.S. high school diplomas or equivalencies, or be honorably discharged military veterans. It will take two months to put the protections in place, according to the Department of Homeland Security.

Deportations of DREAM Act-eligible immigrants have slowed since last summer, when Obama administration officials lessened their focus on certain immigrants, including those with no criminal record or who arrived in the country as children. Instead, they turned their focus to dangerous foreign criminals and foreigners deemed national-security threats.

Homeland Security Secretary Janet Napolitano said in a statement Friday that immigration laws are not designed “to remove productive young people to countries where they may not have lived or even speak the language.”

The new policy, a directive known as “deferred action,” protects an immigrant from deportation for two years, with renewal at the discretion of immigration authorities. A future administration could choose not to renew the protections — a point Republican presidential candidate Mitt Romney made when he briefly spoke to reporters at a campaign stop in Milford, N.H.

“An executive order is, of course, just a short-term matter that can be reversed by subsequent presidents,” said Romney, who has said he would veto the DREAM Act as president.