He's retaining his Canadian citizenship ...
I don't think that America supports much dual citizenship.
I tried to find details explaining it on a government site but could not (quickly). Here is a website that went into it. If Petah had been born in Canada to American parents (and raised in America) then he might have qualified. I beleive that our loyalty oath prohibits dual alligence.
Dual Citizenship FAQ: Dual Nationality and United States Law
Countries usually frame their citizenship laws with little or no regard for the citizenship laws of other countries. In my son's case, for instance, the US does not care that Canada thinks he is a Canadian citizen, and Canada does not care that the US thinks he is a US citizen. Sometimes a country may seek to restrict dual citizenship by requiring one of its citizens born with some other citizenship to renounce (give up) the other citizenship upon reaching adulthood. Newly naturalized citizens may similarly be required to renounce their previous citizenship(s); the US has such a requirement, for example, but Canada does not. In some cases, a country will automatically revoke the citizenship of one of its citizens who acquires another country's citizenship by naturalization, even if no explicit renunciation was involved.Where one country requires a citizen to renounce the citizenship of another country, this renunciation may or may not be recognized by the other country. This can sometimes lead to sticky legal situations. Also, countries which require such renunciations differ in how seriously they treat this requirement. In some cases (such as Singapore), an applicant for naturalization may be required by his new country to go to an embassy or consulate of his old country and renounce his old citizenship in a manner prescribed by his old country's laws. Other countries (such as the US in recent years) may treat their own naturalization oaths' renunciatory language as essentially meaningless and take no steps to enforce it at all.