President Obama on Wednesday marked the 50th anniversary of President Lyndon B. Johnson's “War on Poverty” and said the effort was “far from over” as he pushed his own economic initiatives to help the nation's poor.

“These endeavors didn’t just make us a better country. They reaffirmed that we are a great country,” said Obama in a statement. “They lived up to our best hopes as a people who value the dignity and potential of every human being. But as every American knows, our work is far from over.

“In the richest nation on Earth, far too many children are still born into poverty, far too few have a fair shot to escape it, and Americans of all races and backgrounds experience wages and incomes that aren’t rising, making it harder to share in the opportunities a growing economy provides,” he added.

Obama has said that tackling income inequality would be the central focus of his second term, calling it the “defining challenge” of our time. The president has urged lawmakers to pass a number of measures he says will bolster the middle class.

“We must redouble our efforts to make sure our economy works for every working American. It means helping our businesses create new jobs with stronger wages and benefits, expanding access to education and health care, rebuilding those communities on the outskirts of hope, and constructing new ladders of opportunity for our people to climb,” said Obama in his statement.

On Wednesday, the White House said Obama would announce five “Promise Zones” where the government would provide tax incentives and grants to help communities address poverty. The first Promise Zones will be in San Antonio, Philadelphia, Los Angeles, southeastern Kentucky and the Choctaw Nation.

But Obama’s economic agenda faces opposition from conservative Republicans.

The president is pushing the GOP-controlled House to pass an extension of unemployment benefits for 1.3 million out of work Americans. But Republicans are split over whether the jobless benefits should be offset by budget cuts.

Obama’s effort to redirect focus on economic issues comes amid the toughest stretch of his presidency, with polls showing him at record lows in approval rating following the botched rollout of his health care law.