Pope Francis has recorded a video message at the Vatican offering New Years greetings to two million revelers, including around 800,000 tourists, preparing to party on Rio's famed Copacabana beach.
The message, which will be broadcast as the city also celebrates 450 years of existence, "will be presented just before the traditional midnight fireworks display," a Rio city hall spokesman said, confirming that it had been received Monday.
"Dear Brazilian people, it is with great joy that I address you on the eve of a new year marking the start of celebrations commemorating 450 years since the foundation of the city," the pontiff will tell revelers.
The New Year fireworks display will see 34,000 rockets and 24 tons of fireworks launched on the stroke of midnight from 11 boats anchored 400 meters (440 yards) from the shoreline.
The fireworks will also include letters and figures, forming the slogan "Rio450" in the night sky.
In the video, the pope says he is greeting "at such a happy moment the beloved 'Carioca' people."
Many Rio locals, nicknamed Cariocas, will dress in white and make a traditional offering of garlands of flowers to Yemanja, goddess of the sea in the Candomble Afro-Brazilian faith.
With Brazil entering high summer, temperatures were today hovering around 40 Celsius (104 Fahrenheit) and no rain was forecast ahead of the celebrations.
Rio city authorities have drafted some 3,600 police to maintain security along the 4.5-kilometer (2.5-mile) beach.
When the pope, from neighboring Argentina, visited Rio in July 2013, some three million people gathered in Copacabana beach for a mass which closed a Catholic youth festival.
