Mayor Bill de Blasio began a cross-country trip to unveil his progressive agenda in Washington Tuesday, where he urged elected officials to help rebuild the middle class.

The mayor appeared alongside Massachusetts Sen. Elizabeth Warren, one of the nation's most well-known progressives.

During his speech, de Blasio urged officials to make changes that will end income inequality.

"We in New York are doing all we can. But we can not complete the mission without fundamental change in federal policy. And there needs to be not only a new debate in this country, but there needs to be a movement that will carry these ideas forward," De Blasio said.

The mayor is expected to give one more speech on Capitol Hill about infrastructure programs.

After that, his next stop is California, where he will deliver a speech on income inequality and hold a fundraiser.

He has given similar speeches in Iowa, Nebraska and Wisconsin.

Prior to his departure, de Blasio defended his time on the road as beneficial for the city.

"I also have to participate in changing the national debate, and changing the reality in Washington in a way that will support the people of New York City. We've gotta do both at once," de Blasio said.

During an interview with Rolling Stone last week, the mayor said his work is more appreciated by people outside the city than by his own constituents.

He's expected to return on Saturday.