Russia's sports minister says the country has a "problem" with doping and is "very sorry" that its cheating athletes were not caught sooner.
Russia, a track and field powerhouse, was suspended by the IAAF in November following a WADA panel report that found state-sponsored cheating.
Writing in British newspaper The Sunday Times, Vitaly Mutko said "serious mistakes have been made by the federation management, along with athletes and coaches who have broken anti-doping rules ... Let us be clear. We are ashamed of them."
Russia will discover on June 17 whether its athletics federation has met the reform criteria to return to competition in time for the Rio de Janeiro Olympics.
Mutko says Russia has done "everything that has been asked of us by the IAAF in order to be reinstated."