"The docking has taken place," said the Mission Control Centre.
The docking of Soyuz MS-14 spacecraft with the Russian Fedor, short for Final Experimental Demonstration Object Research, robot took place several minutes ahead of the schedule, it said.
The docking was rescheduled after a failed attempt on August 24.
During the first attempt of docking, a fault occurred in the ISS equipment responsible for the safe approach and airlocking, and then the Mission Control Centre decided to withdraw the spacecraft to a safe distance to ensure the safety of the crew and the station.
The Soyuz MS-14 was launched on August 22 from the Baikonur Cosmodrome in Kazakhstan, with the robot. Fedor is expected to remain at the station for 14 days, Efe news reported.
The Russian space agency, Roscosmos, has set up several experiments for Fedor, which the robot will report on its Twitter and Instagram account, before returning to Earth.
Fedor's trip into space was advertised with much fanfare in Russia and it is expected to return to the station in 2021.
The robot has also been chosen to pilot the new Russian spacecraft "Federation", whose launch has been postponed until 2022, and it could become the first to travel to the moon.
The ISS is currently manned by the Russ Alexsey Ovchinin and Alexander Skvortsov, Americans Andrew Morgan, Nick Hague and Christina Koch, and the Italian astronaut of the European Space Agency, Luca Parmitano.
( With inputs from IANS )