A vehicle that may be carrying a ballistic missile was spotted at a parade training ground in North Korea in a sign it is preparing a big military display for an October 10 holiday, a US think tank said.
Commercial satellite imagery taken on Tuesday showed a "probable missile-related vehicle" at the Mirim Parade Training Ground outside the capital, Pyongyang, according to a report by the group 38 North, which monitors North Korea.
"While imagery resolution is insufficient to determine exactly what the vehicle is, relative size and shape suggests that it may be a transporter-erector-launcher for a large missile," the group said.
The vehicle appeared to be large enough to carry one of North Korea's intercontinental ballistic missiles, which are believed to be capable of delivering a nuclear warhead to targets as far as the US.
The group said the chance the vehicle was something else seemed "unlikely in this particular location and circumstance".
Satellite imagery also showed large formations of troops and vehicles practising at the parade training ground, 38 North reported.
"The recent training strongly suggests a large military parade is planned for the 75th anniversary of the Workers Party of Korea on October 10," it said.
North Korea has not shown its largest ballistic missiles at military parades since early 2018, when leader Kim Jong-un began a flurry of diplomatic engagement that included three meetings with US President Donald Trump.
But talks aimed at getting North Korea to give up its nuclear programme have since stalled and this year Mr Kim vowed to unveil a new "strategic weapon".
Analysts said North Korea could use the holiday to reveal new weapons, either at a parade or in a test.
US officials said this week that North Korea resumed long-range missile co-operation with Iran but did not provide detailed evidence.