World Cup holders Germany and the FIFA confederations champions compete in the eight-team tournament which will put Russia's ability to handle thousands of visiting and home fans under the spotlight.
Security will be a concern over the two weeks in stadiums which have been dogged by construction delays and structural problems.
Next year's World Cup will take place in 12 stadiums spread across 11 cities, including Moscow, St. Petersburg, Kazan and Sochi, the host cities for the Confederations Cup.
The Krestovsky Stadium has been mired in scandal, taking over a decade to build at an estimated cost of $800 million, amid allegations of corruption.
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A new pitch had to be laid hastily after the old one broke up during test games this year, but organisers insist the 68,000-seater arena is ship shape for the June 17 opener and July 2 final.
"We're completely ready for the tournament," Russia's deputy Prime Minister Vitaly Mutko told Friday's press conference.
"The infrastructure, hotels, transportation systems -- everything's ready. And we've took the full-scale measures to assure the event's security. Welcome to Russia
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FIFA Secretary General Fatma Samoura said Russia's readiness had "surpassed expectations".
"We have visited Moscow and the St Petersburg stadium and I can say that every technical detail there has been fine- tuned and we can expect one of the best competitions ever here in Russia," said the Senegalese FIFA official.
"The Confederations Cup is the main operational milestone on the way to the next year's World Cup.
"It is the experience and knowledge that will be of enormous value for 2018."
Heavyweights Germany will clash with Asian Cup champions Australia, Africa Cup of Nations winners Cameroon and Copa America holders Chile in Group B.
And Samoura said that 480,000 tickets had already been sold -- 60 percent of the overall total.
"As much as 44,000 tickets have been sold for the opening match in St Petersburg with 24 hours remaining before the kick-off," Samoura added.
"And the match between Russia and Portugal has been sold out several weeks ago."
Russian authorities insist there is almost no chance of a repeat as police have cracked down on suspected troublemakers with a barrage of searches, detentions and criminal probes.
Some 191 fans have been put on a blacklist barring them from games and legislation introduced to toughen up punishments and deport foreign hooligans.
"The clashes between the fans in Marseille last year were ugly," Alexei Sorokin, the CEO of Russia's organising committee, told AFP in a recent interview.
"We're confident that the Confederations and World Cup in Russia will be completely safe.