A prototype of Russia's new strategic bomber, the PAK DA, could take to the skies before 2021.

The PAK DA is a under development by the Tupolev Design Bureau, state-owned Sputnik News reported. It is to be a "flying wing" type of aircraft and will replace the Russian Air Force's Tu-160, Tu-95MS and Tu-22M3 bombers.

"Work on the PAK DA is coming along and the pace is suiting us," the news agency quoted Viktor Bondarev, chief of Russia's Air and Space Forces. "The challenge remains to raise the prototype into air by 2021, but if all continues at the current pace, it will take off even earlier."

The bomber will fly at subsonic speeds and feature stealth technology for reduced visibility to radar.

Long-Range Aviation Commander Lieutenant-General Anatoly Zhiharev earlier described the PAK DA as "a fundamentally new plane with a new sighting and navigation system."

"This plane will be equipped with the latest communication systems and electronic warfare, and will have little visibility to radar," he said.