Bourenkov told Russian media that "projects involving [human] flight into deep space can only be international in nature. If a trip to Mars takes place, it will be with Russia's participation."
Bourenkov added that without accounting for Russia's vast experience in manned space flight, as well as unmanned flight to other planets, including Mars, a manned mission to Mars will be next to impossible. "In general, this is an area for international cooperation," Bourenkov noted.
Bourenkov added that rocky diplomatic relations between Russia and the US do not have to impede on international space cooperation, citing the fact that Russian cosmonaut Mikhail Kornienko and US astronaut Scott Kelly are scheduled to travel to the International Space Station later this month; their stay onboard the station is set to last a year, which will be a new record for the ISS.
NASA has recently tested a super-heavy rocket for manned trips to Mars. Plans exist to send astronauts to the Red Planet after 2020.