Dressed in white T-shirts that read "Bring Isa Home," Becky and Sergio Celis pleaded in front of TV cameras for whoever has their "baby girl Isabel" to make their demands known.
"Just please, please, the person or persons who have Isabel, tell us your demands. Tell us what you want. We will do anything for her," Sergio Celis said while choking back tears.
The couple said they are increasing a reward that is being offered for information about the case. They also expressed gratitude to investigators and to people who have prayed for Isabel.
Surrounded by friends and volunteers who have been passing out fliers, Sergio Celis also promised that the search for his daughter would never end.
"We are looking for you, Isa. We love you and we miss you so much. We will never give up," he said.
The parents did not take questions from reporters who were gathered in a shopping center parking lot where police had established a command post.
This was the first time Isabel's parents spoke publicly since Isabel was reported missing Saturday. The first-grader's parents have told police they last saw her in her room Friday night and they awoke Saturday to find her missing. Police said a window was open with the screen pushed aside.
Tucson police have said they consider the case a suspicious disappearance and possible abduction.
Police Chief Roberto Villasenor said he still hopes to find Isabel alive. The FBI has brought in specially trained profilers to help.