The security "measures are really unprecedented ... They are based on our experience with such events and we have also studied international experience," said Alexei Lavrishchev, head of security operations in the FSB domestic security service.
At least 600,000 international visitors are expected to travel to Russia for the World Cup, which will see matches played in 11 cities from June 14 through July 15.
Russia hosted the 2014 Winter Olympics in Sochi, which went off without a hitch.
"Today, there are no threats we have detected against the participants and visitors to the World Cup," Lavrishchev told a news conference.
"Nevertheless, after the long years of preparations we have created a clear security plan and we are ready to avert and overcome any security threats..." he said.
Security measures have been stepped up in the cities hosting matches, with some business activities limited and the mayor of at least one city urging residents who don't plan to attend the games to go to their country homes.
Anton Gusev, the interior ministry's point man for the World Cup, said all of Russia's various police and security forces have been mobilised to ensure safety.
He declined to provide a number of police and security forces staff that have been assigned to the World Cup.
Russia has more to worry about than violence breaking out among football fans. Islamic State and the Al-Qaeda have made numerous threats against the country since Moscow intervened in the Syria conflict.
FIFA, the world football governing body, has said it has full confidence in Russia's ability to ensure security for the World Cup.