The president, who has repeatedly called for an overhaul of U.S. immigration laws, praised the activists for their "sacrifice and dedication" during their 17-day-old "Fast for Families."
"The president told them that it is not a question of whether immigration reform will pass, but how soon," a White House statement said. "He said that the only thing standing in the way is politics, and it is the commitment to change from advocates like these brave fasters that will help pressure the House to finally act."
The Obamas talked with fasters, including organizers Eliseo Median and Dae Joong Yoon, for about 30 minutes.
Vice President Joe Biden, Agriculture Secretary Tom Vilsack , Secretary of Labor Tom Perez and Senior White House Adviser Valerie Jarett are among the administration officials who have visited with the activists during their fast which continued over the Thanksgiving holiday.
Michelle Obama tweeted earlier this week: "As families begin to gather for Thanksgiving. I'm thinking of the brave #Fast4Families immigration reform advocates. We're with you. -- mo"
A bipartisan immigration reform bill passed by the U.S. Senate has failed to be called for debate in the Republican-controlled House. It calls for an eventual path to citizenship for immigrants in the country illegally while stepping up border security.