The blastoff of the Soyuz MS-13 manned spacecraft to the International Space Station (ISS), scheduled for 6 July, from the Baikonur space center, may be delayed for two weeks at the request of NASA, a source in the Russian rocket and space industry told Sputnik on Thursday.

"The American side asked the Russian side to postpone the launch of the Soyuz MS-13 for two weeks — from 6 to 20 July, as well as to extend its flight for two months — from December 2019 until February 2020", the source said.

He said this would allow NASA to ensure the presence of not one but three astronauts in the US segment of the space station until February 2020 in case of delays in testing new US manned spacecraft.

Earlier, Russian state space corporation Roscosmos said the blastoff of the Soyuz MS-13 spacecraft to the ISS is slated for 6 July.

However, the United States will extend the use of Russian Soyuz spacecraft to bring NASA astronauts to the International Space Station and ensure their return to Earth until April 2020, a Russian space industry source told Sputnik earlier.

Earlier in March, the Soyuz MS-12 spacecraft has successfully docked to the International Space Station, bringing a new crew to the orbital outpost. The current ISS crew comprises Russian cosmonaut and Commander Oleg Kononenko, Russian cosmonaut Alexey Ovchinin, Canadian astronaut David Saint-Jacques and US astronauts: Anne McClain, Nick Hague and Christina Koch.