Specialists are analyzing the situation, Roscosmos said, without providing further details.
Luna-25 is Russia’s first attempt to land on the moon since 1976. The unmanned spacecraft took off from the Vostochny cosmodrome in Russia’s eastern Amur region on Aug. 11 local time.
It has already sent back images of the moon’s Zeeman crater, and was expected to make a landing on Monday — two days before an Indian mission is set to touch down. Their race to land on the south pole of the moon comes amid a rush to establish a lunar presence from countries including the United States and China.
Russia’s lander has a 1.6-meter-long (around 5-foot-3-inches) robotic arm with a scoop to collect rocks, soil and dust. It is expected to operate for a year on the lunar surface on a mission to study the composition of the south pole, where NASA and other agencies have detected traces of frozen water.
Access to that ice is vital to any human settlement, The Washington Post reported — the water not only can sustain life, but its component parts of hydrogen and oxygen also can be used as rocket fuel, potentially positioning the moon as a springboard to other parts of the solar system.