(CNN)North Korea appears to be preparing for another missile test, according to a US Defense official. The official said that transporter vehicles carrying ballistic missile launching equipment were seen arriving in Kusong, North Korea on Friday. The official said that when such equipment is seen, a launch could occur within six days, which would coincide with the upcoming July 27 North Korean Holiday celebrating the armistice which ended the Korean War.

Last Wednesday, CNN reported that US intelligence indicated that North Korea is making preparations for another intercontinental ballistic missile (ICBM) or intermediate range missile test. Two administration officials familiar with the latest intelligence confirmed they'd seen indicators of test preparations. US satellites have detected new imagery and satellite-based radar emissions indicating that North Korea may be testing components and missile control facilities for another ICBM or intermediate launch, officials say.

Kusong has been the site of North Korean missile tests in the past, including a May test of a KN-17 intermediate range missile which traveled almost 500 miles before splashing down in the Sea of Japan/East Sea, hitting the water about 60 miles from Vladivostok in eastern Russia, according to US officials.