MOSCOW — Russia and the World Anti-Doping Agency were once again at loggerheads Thursday following WADA’s demand that the Russian government must accept the findings of a report which accused its officials of overseeing a mass doping cover-up.

The dispute comes a day before the start of the track and field world championships in London, which will feature 19 Russians officially competing as “neutral athletes,” with many others prevented from taking part. Arguments over past doping offenses could delay Russia’s full return to international competition.

Last year’s report by WADA investigator Richard McLaren said Russian Sports Ministry officials decided which athletes to “save” by covering up failed drug tests, and oversaw a plan to swap samples containing banned substances at the 2014 Winter Olympics.

In a new road map, WADA has made acceptance of the report by the ministry and Russian Olympic Committee a key point as Russia tries to have its national drug-testing agency, known as RUSADA, reinstated.

“There was no state program and there cannot be one, this didn’t happen in Russia,” Deputy Prime Minister Vitaly Mutko told Russian news agency Tass on Thursday. “We will not admit something that did not happen.”

Some ministry officials resigned last year following McLaren’s allegations, but the government has never said they were responsible for any of the abuses alleged in the report, which concerned dozens of sports and hundreds of athletes over several years.

Vitaly Smirnov, the head of an anti-doping commission set up by Russian President Vladimir Putin, disputed another of WADA’s stipulations — that Russian law enforcement stop sealing off a store of urine samples in Moscow’s former drug-testing laboratory. “There’s no way we can speed up this process,” he told Russian agency R-Sport.

The investigation by the Russian Investigative Committee has so far concentrated on former lab director Grigory Rodchenkov — the McLaren report’s star witness — painting him as an immoral and unreliable figure who coerced otherwise clean athletes into taking drugs.

The road map acknowledges progress on RUSADA’s administration and anti-drug education programs, but says it must still hire more staff and pass an audit.

WADA’s demands will likely have little immediate effect because WADA has already partially restored some authority to RUSADA. That allowed it significant independence, including the authority to coordinate drug testing.

Russia previously said it hoped for full WADA reinstatement in November, which would be two years since RUSADA was first suspended on suspicion of covering up for drug cheats.

RUSADA reinstatement is required for Russia to make a full return to track and field.