Russia has unveiled a new-generation battle tank called Armata T-14 ahead of World War Two Victory Day celebrations on 9 May.
It is among several new weapons systems featuring in a vast parade on 9 May. It is 70 years since the Soviet and Allied armies defeated Nazi Germany in 1945.
The Russian defence ministry has posted photos of the new military hardware, taken during a rehearsal.
Most Western leaders will not go to Moscow because of the Ukraine crisis.
Russia's former World War Two allies - the UK, France and US - will be conspicuously absent from the event. The Red Square spectacle is expected to be the biggest military parade ever held.
How big is the Moscow parade?
- 15,000 Russian troops
- 1,300 foreign troops, including Serbian elite guards, Chinese guards of honour and Indian grenadiers
- 200 armoured vehicles
- 150 combat aircraft
The Armata tank has an unmanned turret and a 125mm smooth-bore cannon that can fire guided missiles as well as shells.
The three-man crew has better protection than in existing Russian tanks. They will be housed in a reinforced chamber, away from the main gun, Russian media report.
Zvezda TV, a Russian defence ministry channel, says the tank's chassis is adaptable as a platform for other weapons systems.
And Russia's RT news says the Armata could "evolve into a fully robotic battle vehicle".
Its computer technology, speed and manoeuvrability are said to be far superior to those of the T-90, the current mainstay of the Russian army.
Russia plans to bring in about 2,300 Armatas, starting in 2020, to replace Soviet-era tanks.
Russia's annexation of Crimea and help for rebels in eastern Ukraine triggered Western sanctions, targeting senior government officials, defence industries and the energy sector.
The Kremlin sent dozens of invitations to foreign leaders, but many will stay away from the 9 May parade.
Germany's Chancellor Angela Merkel will not be there for 9 May, but will visit the following day.
German Foreign Minister Frank-Walter Steinmeier plans to travel to Volgograd - formerly Stalingrad - on 7 May. Nazi troops were defeated there in one of the bloodiest battles in history.
Chinese and North Korean leaders will be among foreign dignitaries at the 9 May parade.
Serbia - a candidate for EU membership - sent an elite guards unit to Moscow on Monday. They will be among several foreign contingents in the march-past.
Greece's left-wing Prime Minister Alexis Tsipras plans to attend the parade.