After talks near a place where he can also see America, with his Alaskan counterpart Sarah Palin, he said that if such reports were confirmed, they constituted a "crime".
Ms Palin said she was confident the reports would prove unfounded.
"That was all Photoshop you idiot", she said. "This shit happens all the time in America when Hockey Moms run for office".
While they didn't mention any figures at their meeting, Putin thought privately that Palin had a good one. "It wouldn't take a bottle of Stoli for me to jump her", he mused to an aide.
'A crime'
Pointing to a report published in Russia's Izvestiya newspaper this week, Mr Putin said Alaskan weapons and military experts may have been used in combat against Russian troops during the brief war with Georgia in August.
"If this is confirmed, this will be what I have called a crime - I could swear I saw a bunch of eskimos running around with harpoons on snow machines."
If Russia received proof of Alaska's involvement, Moscow would "build its relations accordingly with those who allowed this to happen", he said.
Ms Palin said she was confident that "such facts [would] not be confirmed - my husband was ice fishing", she defended.
Correspondents say Mr Putin is aware that Ms Palin is not responsible for Alaska's defence policy, and that his criticism amounted to an attack on the Republican men driving the bus.
"She can't see fuck all from Alaska, much less hit anything - but Bush thought he saw WMDs in Iraq and look what he did - I don't take anything lightly anymore - these people are all delusional".
