"Trust is not going to come over night, it is not as if you make five changes and trust will follow in two weeks' time," Sebastien Coe told the BBC on Sunday.
An independent commission of the World Anti-Doping Agency (Wada) said in the second part of a damning report on Thursday that "corruption was embedded" at the International Association of Athletics Federations (IAAF).
"It may be the case that trust does not return until way beyond my term in office," Coe added, although he came off relatively unscathed in the Wada report.
Its co-author Dick Pound even said he thought the double Olympic 1500 metres champion was the best man to reform the sport.
The Briton, who was elected president in August, said he took some comfort that the report found that the IAAF's systems were not chronically broken and that officials were not "asleep on the job".
There have been numerous calls to reset all the records in the sport and ban any British athlete found to have cheated for life, in a bid to restore the public's confidence.
Six-times Olympic champion Usain Bolt said he felt shocked and let down by the burgeoning corruption scandal, but the Jamaican sprinter was against resetting athletics world records.
The bulk of criticism has centred on Russia.
Moscow was banned from the sport indefinitely after the first Wada report, which found a "deeply rooted culture of cheating" in Russian athletics.
On Saturday the country appointed a new anti-crisis chief to salvage its reputation in time for the Olympic Games in Rio de Janeiro.