Putin gets sneak peek of 'Checkmate' stealth fighter jet
"The head of the Rostec state corporation, Sergei Chemezov, and the general director of United Aircraft Corporation, Yury Slyusar, showed Putin the new Checkmate fighter jet," Rostec said in a statement.
The aircraft was being kept in a hangar with the words "The Checkmate" written in large white lettering in English, according to an AFP photographer at the exhibition.
The official unveiling is scheduled for 1500 GMT Tuesday.
But the plane will not perform any flights, a Rostec spokesman told AFP.
Putin praised Russia's aviation industry as he unveiled the biennial MAKS air show earlier Tuesday.
"Russian aviation has great potential for development, and our aircraft industry continues to create new competitive aircraft," Putin said.
Putin has made investing in the army and developing new weaponry a priority over his two-decade rule.
Russia has boasted of developing several weapons that circumvent existing defence systems, including the Sarmat intercontinental missiles and Burevestnik cruise missiles.