An unmanned Russian cargo spacecraft ferrying supplies to the International Space Station is plunging back to Earth and apparently out of control, an official told AFP.

"It has started descending. It has nowhere else to go," an official familiar with the situation said on condition of anonymity, speaking ahead of an official Russian space agency statement expected later in the day. "It is clear that absolutely uncontrollable reactions have begun."

Russia loses comms with ISS cargo spacecraft
Astronauts aboard the International Space Station were left with a long wait Tuesday to get their latest food and fuel deliveries after an unmanned Russian supply ship lost communications following takeoff.

The ISS crew won't actually be in danger of going hungry -- the station has plenty of supplies -- but the Progress supply craft's normal six-hour voyage has been extended to two days.

And even then, the wait may not be over: with the Progress circling Earth in radio silence Tuesday, it could be just days before it runs out of fuel and starts an uncontrolled descent back into to the atmosphere.

Russian mission control told AFP that the Progress's problems began soon after launch.

"The ship reached orbit but the full volume of telemetry (data transmissions) is not being received," a spokesman said.

As a result, the controllers had opted to change the flight plan and extend the vessel's usually brief journey six hours to two full days.

The mission control website stated later Tuesday that the ship would dock with the ISS, where the international crew of six people awaits the cargo, on April 30.

NASA said however that the ship was not responding, and the extra time would be used for "troubleshooting of rendezvous antenna deployment" which is necessary for the docking to the station.

Live NASA commentary said Russia's mission control sent commands as the ship made two passes over Russia but still "no data was received."

The ship contains necessary equipment for the station, as well as water, food, and clothing for the people on board, as well as over one tonne of fuel.

Roscosmos space agency said earlier this month that the ship would also carry a copy of the Soviet Victory Banner: the red flag three Red Army soldiers raised over the Reichstag building in Berlin on May 1, 1945.

The flag, which is the official symbol of Soviet victory over Nazi Germany that Russia will commemorate on May 9, was to be used by Russian cosmonauts to send their greetings to the nation on that day.

A Soyuz rocket carrying the Progress M-27M supply craft launched successfully from Russia's Baikonur cosmodrome in Kazakhstan earlier Tuesday.

An engine mishap on a similar Progress flight in 2011 led to complete loss of communication failure to reach the target orbit.

A few weeks later it crashed into Siberia in one of Russia's biggest space setbacks.

Three or four Progress cargo ships are launched every year bringing necessities like oxygen, fuel and food supplies to the orbiting laboratory. After completing their mission they usually fall into the Pacific Ocean.