Travis Tygart, the U.S. Anti-Doping Agency chief, says Russia has only been emboldened by previous sanctions for its doping violations and the four-year ban imposed on Monday will do nothing to change its behaviour.
Russia was banned from the world's top sporting events for four years on Monday, including the next Summer and Winter Olympics and the 2022 soccer World Cup, for tampering with doping test data.
The World Anti-Doping Agency (WADA) executive committee acted after concluding that Moscow had planted fake evidence and deleted files linked to positive doping tests in laboratory data that could have helped identify drug cheats.
The ban comes as a huge blow to Russian pride and President Vladimir Putin said on Monday that Moscow might appeal the decision, as is their right within 21 days.
WADA's move does leave the door open for "clean" Russian athletes to compete as individuals in Tokyo without their flag or anthem, a decision Tygart has described as "yet another devastating blow to clean athletes".
"Their behaviour hasn't changed," he told Reuters in an interview.
"It has only gotten emboldened and become more egregious every time the global anti-doping community attempts to put a sanction in place.
"The question is – are we just going to stick our head in the sand and pretend this didn't occur and try to turn the page?"
Russia has been embroiled in doping scandals since a 2015 report commissioned by WADA found evidence of mass doping in Russian athletics.
Many of Russia's athletes were sidelined from the last two Olympics and Russia was stripped of its flag and national anthem altogether in Pyeongchang as punishment for state-sponsored doping cover-ups at the 2014 Sochi Games.
Tygart said Russia has not taken its punishment seriously for what he called "the greatest fraud in Olympic history".
"In the Pyeongchang Winter Games in 2018 we supported a neutral process for athletes but what we've seen is that has turned into a complete charade and mockery when you have a full delegation from Russia and we know the behaviour has not changed," he added.
Monday's sanctions, which also include a four-year ban on Russia hosting major sporting events, were recommended by WADA's compliance review committee in response to the doctored laboratory data provided by Moscow this year.