The White House on Wednesday will designate a swath of Los Angeles a "Promise Zone," a move intended to marshal millions of dollars in federal resources for pockets of poverty under a signature program of the Obama administration.

Marking the 50th anniversary of President Johnson's launch of the War on Poverty, the White House will name five communities across the country to be targeted. L.A.'s Promise Zone stretches through Pico-Union, Westlake, Koreatown, East Hollywood and Hollywood, what Mayor Eric Garcetti called some of the "toughest, challenged areas" in the city.

Federal money would be used to help improve education, housing and public safety. The designation gives selected cities preferential status for federal grants. Garcetti said he expected L.A. to get tens of millions of dollars. The most the city could receive is about $500 million over 10 years, according to the mayor's office.

"This will make a material difference," Garcetti said in an interview.

Garcetti will travel to the White House and meet with President Obama on the initiative Thursday.

The federal grants would come from numerous agencies, including the departments of Education, Agriculture, Justice, and Housing and Urban Development.

Garcetti said a "wraparound" approach of federal aid could help alleviate poverty. "For decades, we've put programs in silos, which might move the dial a little bit here on education, a little bit here on health, but never all together, and I think this is our best shot."

The White House said Los Angeles' funding would go toward increasing affordable housing, investing in public transit lines and bike lanes, and giving people more access to career and technical training opportunities through a partnership with the Los Angeles Community College District.

Money also would go to the L.A. Unified School District and the nonprofit Youth Policy Institute to increase the number of support services at schools. The institute has received $32 million to provide tutoring, mentoring, staff support, and after- and before-school care to 20 schools. The city wants to use the federal grants to increase the number of schools in the program to 45, said Dixon Slingerland, executive director of the institute.

"L.A. never gets the big-picture signature presidential initiatives," Slingerland said. "People on the East Coast don't think we have our act together, don't think we can work together, think that we're too spread out.

"We've really begun to sort of change that narrative."

The four other areas being targeted are San Antonio, Philadelphia, southeastern Kentucky and the Choctaw Nation of Oklahoma. The designation lasts for 10 years.

The plan to ultimately team with 20 of the hardest-hit towns in the U.S. was introduced by Obama during his 2013 State of the Union address.

soumya.karlamangla@latimes.com

Twitter: @skarlamangla