SEOUL (Reuters) - North Korean troops have been spotted in commercial satellite imagery preparing for a likely military parade, according to two organisations that track the country.

       Possible dates for such an event are unconfirmed, but North Korea has used recent parades to unveil new military hardware, including large ballistic missiles.

       "Practice for big parades generally begins 1-2 months in advance (sometimes more)," the U.S.-based 38 North programme said in a tweet on Thursday https://twitter.com/38NorthNK/status/1433099602924818441, citing a satellite photo that showed troop formations at Mirim Parade Training Ground in Pyongyang.

       This could indicate an upcoming military parade in October, as was seen last year, the group added.

       At that parade leader Kim Jong Un unveiled previously unseen intercontinental ballistic missiles in an unprecedented predawn event that showcased the country’s long-range weapons for the first time in two years.

       Another nighttime military parade was held in January.

       Talks over North Korea's nuclear weapons and ballistic missile arsenals have stalled in recent years. U.S. President Joe Biden's administration has said it will explore diplomacy to achieve North Korean denuclearization, but shown no willingness to ease sanctions.

       "North Korea has used military parades in the past to boost internal resolve and show off its latest weapon developments to the world," NK Pro, a Seoul-based organisation, said in a report on Thursday.

       The NK Pro report https://www.nknews.org/pro/north-korea-preparing-to-hold-military-parade-in-coming-months-imagery/?utm_source=dlvr.it&utm_medium=twitter said satellite imagery showed what appeared to be dozens of military trucks and at least 14 groups of about 300 soldiers each inside the parade training grounds on Monday, and troops were seen again in images from Wednesday.

       "Since daily satellite imagery became commercially available in recent years, the combination of troop formation training and a full parking lot has only appeared just prior to a military parade taking place," the report said.

       Upcoming holidays in North Korea include its national foundation day on Sept. 9, and the anniversary of the ruling party's founding on Oct. 10.

       North Korea may also be looking to commemorate Oct. 8, when Kim will celebrate the 10th anniversary of becoming supreme commander of the armed forces, NK Pro said.

       (Reporting by Josh Smith; Editing by Kim Coghill)