Will NYC Mayor de Blasio be "Ready for Hillary" in 2016?

New York City Mayor Bill de Blasio is "optimistic" about Democratic presidential candidate Hillary Clinton, but he's still staying mum on whether he will be endorsing her for 2016.

"I was impressed by some of the things she said. I was certainly impressed by her speeches on criminal justice reform and on immigration reform. But I think it's normal -- by the way, I would say this about any candidate -- in this time we're in, we actually need to hear a specific vision for change," de Blasio said Wednesday on "CBS This Morning."

De Blasio, who was a guest on "CBS This Morning" for a historic first broadcast from the One World Trade Center, said it's still early in the campaign, however. He stressed he thinks "the world" of the former secretary of state, but it is "absolutely normal to want to hear a vision" for issues he finds pressing.

"I think the challenge this time in our history is income inequality. I think this country is truly in danger if we don't find a way to uplift working people and get people to a decent standard of living again. We have the worst income disparity since the Great Depression, and unfortunately it's worsening all the time," de Blasio said.

The mayor said again that he is "very optimistic" that Clinton will address these issues and pointed to Clinton's "strong and progressive history."

"I particularly point to 1993 when she took on the insurance companies to try and achieve health care reform, way ahead of when it was actually finally done," he said, adding that he thinks Clinton is "one of the most qualified people ever to run for the office."

De Blasio, who announced a "Progressive Agenda to Combat Inequality" on Tuesday in Washington, D.C., said he also wants to hear about progressive taxation and ways of raising wages and benefits. He applauded the Los Angeles City Council for voting on Tuesday to raise minimum to $15 by 2020, but called it an "organic minimum."

"Now today, in New York City and in many other parts of the country, a wage level under $9 an hour as a minimum -- no one actually thinks a family can live on that as one breadwinner. Even with two they would be struggling," de Blasio said. "That's why you think about $15 for a lot of parts of the country, it is an organic minimum and a minimum we'd like to see a lot of people do better [than]. And I think what's happening is there's been a grassroots effort to demand we re-conceptualize what minimum wage is, and actually think about the costs that families face today. And I think that effort has led a lot of governments and a lot of private companies to change their policies."

To hear more about "the basics that so many other countries have" for working families, including paid sick leave, the mayor said a group of progressives will be holding a presidential forum in the fall to ask both Democratic and Republican candidates about solutions on income inequality.

"Mouthing the words is good, but we have to talk about real solutions," de Blasio said. "I think progressive taxations, things like the Buffett Rule, are one of the necessary components for the change, and I think we should hear that from all candidates."