The letter from Los Angeles Mayor Eric Garcetti to President Donald Trump, dated Jan. 9 and made public on Friday, seeks federal aid to "move our unhoused neighbors into shelter, build permanent housing" and supply services to the homeless.

"I appreciate Secretary Carson reaching out to me," Garcetti says in the two-page missive.

"During our conversation he expressed a commitment to working with cities nationwide to help accelerate our progress in addressing this emergency by investing in strong, humane and lasting approaches that can help get people off the street and save lives," Garcetti said.

The constructive tone is a sharp contrast to Trump's rhetoric on Twitter and during previous visits to California, slamming public officials for the growing homelessness crisis.