A satellite launched by North Korea at the weekend has now stabilised in its orbit around the Earth in a step forward from a previous launch in 2012, a US official says.
However, the satellite is not believed to be transmitting any data back to Earth, a second source said.
The satellite was initially tumbling in orbit but has now stabilised, making it more successful than one launched in 2012, which failed to achieve a stable orbit, said the first source, a US official, who did not want to be identified by name, said on Tuesday (local time).
The US government-backed Space-Tracking.org website shows the satellite in an orbit ranging from 473km to 509km and inclined 97.5 degrees north and south of the equator.
"It is in a stable orbit and the report stating that it is tumbling is not valid," Charles Vick, senior technical analyst with GlobalSecurity.org, told Reuters, referring to some US media reports quoting unnamed US officials.
No transmissions from the satellite have yet been detected, Vick added.
North Korea says the Kwangmyongsong-4 (KMS-4) is an Earth observation satellite. It said that the launch, on Sunday morning Korean time, was a "complete success" and that the satellite was making a polar orbit of Earth every 94 minutes.
So far, amateur satellite trackers have not been able to track it.