President Barack Obama, vowing not to delay his agenda as Republicans assume power of both chambers of Congress, said he will seek "lawful" executive actions on immigration before January.

"Before the end of the year, we're going to take whatever lawful actions I can take that I believe will improve the functioning of the immigration system," Obama told reporters Wednesday at a White House news conference.

The president's pledge on immigration sets up a confrontation with the more powerful Republican representation in Congress. Obama had postponed immigration action until after Tuesday's election in spite of his promises earlier this year to act sooner. The delay cost him support of Latino voters, according to polls.