U.S. President Barack Obama used an Independence Day ceremony in which immigrants serving in the U.S. military became citizens on Wednesday to renew his election-year call for new immigration laws popular with an important part of his political base.

According to Reuters, Obama, who is running for re-election in November, seized the opportunity to talk up his recent order lifting the threat of deportation for hundreds of thousands of illegal immigrants who came to the United States as children.

The issue of immigration has become a flash point in Obama's battle with Republican presidential candidate Mitt Romney to win the White House on November 6.

Romney, the former governor of Massachusetts, has advocated a program of self-deportation for illegal immigrants, a proposal that has not gone over well with Hispanics. He accused Obama of being politically motivated with his move last month to give work permits to children of illegal immigrants, but he declined to say he would repeal the policy if elected.

Obama holds a huge lead in polls over Romney among Latinos, though many are disappointed that he has not delivered on a promise to overhaul the U.S. immigration system.