She said that hundreds of children whose papers had been finalized or were in the process of being finalized would benefit from getting visas to leave in accordance with regulations.
"Evertything is disorganized since January 12 and some people are using it to devote themselves to a veritable trade in children," she said.
The 7.0-magnitude quake on January 12 killed 170,000 people, made more than one million homeless and left many children vulnerable in the Americas' poorest nation.
Pierre said Haitian authorities had also been alerted to cases of "recruitment" of children in southern Haiti.
"One man alone has collected 140 children. We are going to act on this case," she said.
About the 33 children stopped on the Dominican border with 10 people from a US Christian group Friday, Pierre said that the Americans had not told customs officials that they were taking the children out of the country.
"It was during an inspection that a police officer noticed that dozens of children were in the bus without passports," she said.
"Currently we are putting together papers for the children, then our social workers will inquire into whether they were stolen or whether they were entrusted by their parents (to the aid workers)," she said.
Some parents came to the care center where the children were now being kept on Sunday, but they were not allowed to take them away, she said.
Pierre said the institute would launch a program for the reintegration of the children.
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