An American prosecutor and Ontario's Attorney General are joining forces in an effort to change a probation order that sent a convicted sex offender to Canada.

Michael Bryant and Erie County District Attorney Frank J. Clark will ask a U.S. judge to change an order that allowed Malcolm Watson to serve his probation in Canada.

It was a decision that Bryant said sparked an international incident.

"When somebody does a crime in the United States, you do the time in the United States," Michael Bryant said Tuesday.

Watson pleaded guilty to endangering the welfare of a child and sexual abuse in the third degree for an incident with a 15-year-old Buffalo, N.Y. student.

The 35-year-old U.S. citizen lives in Fort Erie, Ont. with his Canadian wife and three children. His sentence says he must spend three years on probation and stay out of the U.S.

The decision sparked outrage north of the border. Ontario Premier Dalton McGuinty reacted by saying his province is not a "dumping ground" for American sex offenders.

Those words caught Clark's attention. He and Bryant plan to repeat them before a U.S. judge.

"We're making the argument that yes we have free trade in North America, but that does not include criminals," Bryant told reporters.

"The Assistant District Attorney's office indicated that the public remarks made by Premier McGuinty will be put before the court to indicate the importance of this matter to Canadians and to Ontarians."

If Clark and Bryant's petition to change the probation order is successful, Watson will be forced to leave Ontario and return to New York State.

A decision on whether Watson will be ordered back to the U.S. to serve his jail term should come within two weeks.

With a report from CTV's Paul Bliss