Russia will turn off the lights on the Kremlin for the first time later on Saturday as part of worldwide events for the Earth Hour campaign against climate change, officials said.
The lights illuminating the red brick walls of the iconic landmark in the heart of Moscow will be shut off for an hour starting at 8:30 pm local time (1630 GMT) following a decision by President Vladimir Putin, the Kremlin said in a statement.
The lights will remain on the Kremlin clock and the Russian flag and glowing red stars that top its towers, a spokesman for the presidential administration, Viktor Khrekov, told RIA Novosti news agency.
The floodlighting of the onion-domed St Basil's Cathedral, which stands just outside the Kremlin walls on Red Square, are also to be turned off, along with around 90 other landmark buildings in Moscow, with the switch-off shown live on Russian television.
Earth Hour organisers expect hundreds of millions of people across the globe to turn off their lights for 60 minutes on Saturday night starting at 8:30 pm local time in a symbolic show of support for the planet.
Many of the world's best-known attractions, including the Sydney Opera House, the Empire State Building and the Eiffel Tower will take part.
Russian astronaut Roman Romanenko, currently part of the team at the International Space Station, appealed for broad support of the event, now in its seventh year.
"From here in space we can see very well how much our planet needs protection," Romanenko said in a video statement from the ISS posted on YouTube.
"Its life depends on us, how we treat it, and use its resources. Support the Earth Hour at 8:30 pm on March 23 as a sign that the fate of our Earth is important to you."
"During that hour we will watch the lights go out on the continents and see how Planet Earth gets its hour of rest, Earth Hour."
The International Space Station itself will not be turning off its lights, a source in the space industry told the RIA Novosti news agency.