Russia's space agency said Tuesday its "main priority" is the safety of the International Space Station's crew, after the US accused Moscow of putting the astronauts under threat with a missile strike.

Washington on Monday denounced Russia for conducting a "dangerous and irresponsible" missile test that blew up one of its own satellites, creating a debris cloud that forced the ISS crew to take evasive action.

"For us, the main priority has been and remains to ensure the unconditional safety of the crew," Roscosmos said in its first comments after the US accusations.

The space agency added that its "automated warning system for dangerous situations" was continuing "to monitor the situation in order to prevent and counter all possible threats to the safety of the International Space Station and its crew".

US officials said they were not informed in advance of the test, which generated over 1,500 pieces of trackable orbital debris.

NASA said the crew aboard the orbital outpost -- currently four Americans, a German and two Russians -- were woken up and forced to take shelter in their return ships.

According to space industry analysis company Seradata, the target of the missile was Cosmos 1408, a 1982 Soviet signals intelligence satellite that has been defunct for several decades.

The move has reignited concerns about the growing space arms race, encompassing everything from the development of satellites capable of shunting others out of orbit to laser weapons.