Debris from a satellite destroyed in 2007 by a Chinese missile is in the vicinity of the International Space Station and astronauts are ready to take cover if required, a Russian official said Friday.

The shooting down of the Chinese weather satellite Feng Yun 1C by a ground missile launched from China at the time sparked international alarm and concern about the creation of dangerous space debris.

"If the calculations show that the debris is approaching the station at an unacceptably close range, the six astronauts will receive the order to take shelter in the two Russian Soyuz spacecraft which are docked with the ISS," an official at mission control outside Moscow told the Interfax news agency.

The official described the flight path of the debris as "dangerous" and said it was already too late to carry out a manoeuvre to "divert the station from the rubbish".

The official was not named and there was no further comment from the Russian side.

However NASA spokesperson Kelly Humphries played down the situation, saying that while the debris had been monitored, its distance from the station was substantial.

"A possible conjunction with a piece of the Chinese Feng Yun satellite debris was monitored by ballistics specialists late last night and overnight," the spokesperson said in an emailed statement.

"It was determined, however, that the miss distance is substantial and no debris avoidance manoeuvre will be required."

The shooting down of the satellite was the first known such intercept test by any country in two decades and China's confirmation of the action at the time sparked a sharp rebuke from the United States.