WASHINGTON, April 11 (Reuters) - U.S. intelligence analysts believe a recent military parade in North Korea "probably oversells" the threat its inter-continental ballistic missiles (ICBMs) pose to the United States, according to a leaked document purportedly from the U.S. government.
Reuters has reviewed more than 50 of the documents, labeled "Secret" and "Top Secret", that first appeared on social media sites in March and supposedly reveal details of military capabilities of some US allies and adversaries.
Reuters has not independently verified the documents' authenticity.
While the Pentagon has not vouched for the authenticity of each of the documents, it said on Monday there appeared to have been an "unauthorized disclosure of classified material." It said that photos appear to show documents similar in format to those used to provide daily updates to senior leaders, though some appear altered.
A brief, one-paragraph observation in one of the documents marked "Secret" and seen by Reuters noted that North Korea had paraded an unprecedented number of ICBM-class launchers at an event on Feb. 8 that were "most likely carrying nonoperational systems."
The Pentagon and North Korea's mission to the United Nations did not immediately respond to requests for comment about the North Korea part of the documents.
The document said the North Korean aim was "probably to portray a maturing nuclear threat to the U.S."
"The North paraded these nonoperational systems to portray a larger, more capable missile force than it possesses and to mitigate the risk of damage to its real missiles," the document said.
North Korea continues to develop its ballistic missile program, test-launching dozens of advanced missiles last year despite United Nations Security Council resolutions and U.S.-led sanctions. It has continued the testing this year.
The document added that during the next year, "North Korea will probably be unable to outfit all of the paraded ICBM-class TELs with operational missiles capable of striking all of the US because of testing hurdles and resource constraints."
TEL is an abbreviation for transporter erector launcher, a mobile missile-launch vehicle.
Imagery published by North Korean state media of the Feb. 8 event showed more purported ICBMs than Pyongyang has displayed before and hinted at a new solid-fuel weapon.
The images showed as many as 11 Hwasong-17s, North Korea's largest ICBM, which is suspected to be capable of striking nearly anywhere in the world with a nuclear warhead.
The Hwasong-17 was first tested last year. Alongside them at the parade were what some analysts said could be a prototype or mockup of a new solid-fuel ICBM in canister launchers. North Korea has sometimes displayed mockups in its parades.
Developing a solid-fuel ICBM has long been seen as a key goal for the country, as it could make its nuclear missiles harder to spot and destroy during a conflict.
