FIFA and World Cup chiefs have dismissed a damning Human Rights Watch report suggesting widespread exploitation of construction workers for the Russian tournament.
The spotlight has turned to Russia's staging of the 2018 World Cup as it prepares to host the Confederations Cup, beginning Saturday night (Sunday morning AEST).
Deputy prime minister and World Cup chairman Vitaly Mutko said on Friday Russia was "absolutely ready to start" the Confederations Cup.
FIFA secretary general Fatma Samoura echoed his confidence in the local organising committee's work, saying "a state of readiness is at its best level ... every technical detail has been fine tuned".
Both denied the allegations made in the Human Rights Watch report published earlier this week.
It suggested at least 17 deaths on construction sites and that migrant and local workers were withheld wages and worked in abhorrent conditions including -25 degrees cold.
Newspaper reports have also suggested North Korean workers were compelled to send wages to their government while employed on the troubled Saint Petersburg stadium.
The stadium hosts the opening match of the Confederations Cup - between Russia and New Zealand.
Organising committee chief executive Alexey Sorokin said he "couldn't confirm" the report's findings.
"There has been in excess of 70 inspections on stadium construction sites. The conditions that workers experience have been closely monitored," he said.
"We did not see any infringements or negative signals."
Mutko said journalists could tour World Cup venues and ask workers themselves about their conditions.
Samoura said all recommendations made from venue inspections had been fully implemented.
"We are are concerned about violations of workers rights and like anti-discrimination, there is a zero tolerance policy from FIFA," she said.
Samoura confirmed the sale of 480,000 tickets - or 65 per cent - for the Confederations Cup.
She refused to be drawn on the future of the event, which is yet to be locked in for 2021.
Each World Cup host since 2002 has staged the summer tournament as a prelude to sport's biggest event the following year but Qatar cannot host the tournament in June 2021 due to heat.
FIFA previously advised the next tournament would be held in another Asian nation.
Samoura said she "cannot comment because no decision has been taken on that".
"We want to focus on the current edition," she said.
Mutko, Sorokin and Samoura were speaking at the official pre-tournament press conference in Saint Petersburg on Friday.