MOSCOW (Reuters) - The International Space Station performed a manoeuvre on Friday to temporarily swerve away from a fragment of a U.S. launch vehicle, the head of Russia's space agency said.

       Dmitry Rogozin, who heads Roscosmos, said the station's orbit dropped by 310 metres (339 yards) for less than three minutes to avoid a close encounter with a fragment from a U.S. launch vehicle sent into space in 1994.

       Rogozin added that the manoeuvre would not affect the planned launch of the Soyuz MS-20 rocket on Dec. 8 from the Baikonur cosmodrome in Kazakhstan and its docking at the ISS.

       Space debris, or space junk, consists of discarded launch vehicles or parts of a spacecraft that float around in space and risk colliding with satellites or the International Space Station.

       Space debris forced NASA on Tuesday to postpone a spacewalk placed to replace a faulty antenna at the ISS.

       U.S. officials also said last month that an anti-satellite missile test carried out by Russia had generated a debris field in low-Earth orbit that endangered the ISS and would pose a hazard to space activities for years.

       (Reporting by Gabrielle Tétrault-Farber; Editing by Kim Coghill)