The United States has denied powerful electromagnetic emission from a U.S. radar caused the failure of a Russian spacecraft that fell to Earth.

"We have seen speculation in the Russian media that foreign interference might have contributed to the failures of several recent Russian space missions," U.S. State Department spokesman Jamie Mannina said. "We do not believe there is truth to these reports."

U.S. specialists had responded to a request from the Russian federal space agency Roscosmos and had assisted Russia in its efforts to establish contact with the Phobos-Grunt Mars mission spacecraft, stranded in Earth orbit in November after its engines failed to send it towards Mars, Mannina said.

"Although recovery attempts by several nations ultimately proved unsuccessful, the United States cooperated with Russia and other nations to monitor the final orbits and uncontrolled re-entry of the Phobos-Grunt spacecraft into the Earth's atmosphere," he said.

Roscosmos head Vladimir Popovkin said a government commission looking into the crash blamed manufacturing errors and engineering flaws for the failure of the Phobos-Grunt mission and that the U.S. radar is viewed as potentially "only as one of the causes," RIA Novosti reported.

Roscosmos is expected to hold tests to see whether the probe was affected by U.S. radars that may involve NASA specialists.