DETROIT (AP) — Only hours after agreeing to resign and serve time in jail as part of plea deal, Mayor Kwame Kilpatrick expressed regret for the scandal that has engulfed the city — and left the door open for a return to public life.

Kilpatrick walked into a City Hall conference room Thursday to thunderous applause and thanked his family, backers and staff members for sticking by him during his rocky 61/2-year tenure.

‘‘I truly know who I am. I truly know where I come from. In Detroit I know who I am. And I know because of that, there’s another day for me,’’ he said in a 20-minute speech on live television. ‘‘I want to tell you, Detroit, that you done set me up for a comeback.’’

In exchange for pleading guilty to two counts of obstruction of justice, the Democrat will get four months behind bars, pay the city $1 million in restitution, lose his license to practice law, and cannot run for any elected office for five years.