Updated

In his most specific pledge yet to U.S. Hispanics, President Barack Obama said Saturday he would seek to tackle immigration policy in the first year of a second term. But he cautioned that he would need an amenable Congress to succeed.

"This is something I care deeply about," he told Univision. "It's personal to me."

Obama said in the television interview that he would work on immigration this year, but said he can't get support from Republicans in Congress. Obama also tried to paint his Republican presidential challenger, Mitt Romney, as an extremist on immigration, saying that Romney supports laws that would potentially allow for people to be stopped and asked for citizenship papers based on an assumption that they are illegal.

"So what we need is a change either of Congress or we need Republicans to change their mind, and I think this has to be an important debate during — throughout the country," Obama said.

Romney aides have said that the former Massachusetts governor supports laws that would require employers to verify the legal status of workers they employ.

"President Obama only talks about immigration reform when he's seeking votes," said Romney spokeswoman Andrea Saul. "Then-candidate Obama promised to tackle immigration reform in his first year. More than three years into his term, America is still waiting for his immigration plan."

Hispanics are an increasingly important voting bloc in presidential elections. Obama won a sizable majority of the Hispanic vote in the 2008 election and his campaign is hoping for similar results this November.

Obama spoke to Univision, a network widely watched by Latinos in the United States, while in Colombia for the Summit of the Americas.