But he said he could have unwittingly participated in their use while he was on the high-level military exchange.
For that reason, Natynczyk said Thursday, he defends a controversial clause in Canada's proposed bill that would ratify Canada's acceptance of the Convention on Cluster Munitions.
The clause has opened Canada to heavy criticism — including from the normally neutral International Committee of the Red Cross — that it is watering down a treaty to ban an abhorrent and imprecise weapon that mainly harms civilians.
The clause would allow the Canadian Forces to be involved in the use of the bombs in joint operations with the United States, which has opted out of the convention, while offering legal protection to senior military personnel such as Natynczyk on high-level secondments.
The U.S. dropped an estimated 74,000 cluster bombs that contained 22 million submunitions, or bomblets, on Iraq during its 1991 and 2003 invasions.
"I can say to you in confidence that I was never aware that cluster bombs were actually stocked in theatre, or that I participated in planning for their use or in fact authorized their use," Natynczyk, now the head of Canada's space agency, testified Thursday at the House of Commons foreign affairs committee.
"I had none of that experience whatsoever. However, unwittingly, I could have done so, and I could have participated in activities without my knowledge that assisted in the use of cluster munitions. But I would not have known it at that time."
Natynczyk backed the government's position that cluster bombs are a weapon that ought to be banned. He said he signed an order in 2008 when he was chief of the defence staff, banning their use by all Canadian military personnel.
But Natynczyk also backed the controversial interoperability clause because of Canada's unique military relationship with the U.S.
Natynczyk is one of the prime examples of the privileged access that senior Canadian military officers get with the U.S. In his case, an exchange program led to him being a deputy commander of U.S. forces in a war to which the Canadian government refused to commit its own soldiers.
Liberal MP Marc Garneau asked Natynczyk whether Canada's relations with the U.S. would truly be harmed if it simply advocated an all-out ban on the use of cluster bombs in joint operations.
"I don't know enough of their thinking," Natynczyk replied. "I can't make comment on this."
Also testifying, Walter Dorn, a professor at the Royal Military College of Canada, said the "obnoxious paragraphs" in the controversial clause ought to be excised.
"This sets such a bad precedent for the rest of the world."
Dorn said governments regularly negotiate "caveats" for their troops before joint operations that specify what they will or won't do during the mission.
Dorn cited the well-known caveat from the Afghanistan war that prevented German soldiers from fighting in the country's violent south, the Taliban heartland around Kandahar, where Canadians bore the brunt of a conflict that cost more than 150 military lives.