China has disclosed the first images of secret hypersonic strike aircraft that are being developed to deliver nuclear warheads through U.S. missile defenses.

State-run CCTV on Oct. 8 broadcast images of four different vehicles or missiles that U.S. intelligence agencies believe are mockups of hypersonic strike vehicles, including one known as DF-ZF.

It is the first time images of the hypersonic aircraft were made public.

The Free Beacon first reported China's initial flight test of the hypersonic glider in January 2014. Since then, six other flight tests have been carried out in what U.S. intelligence officials believe is a high-priority weapons program for the Chinese.

China's Defense Ministry confirmed the first flight test nearly four years ago but sought to play down the arms development.

"Our planned scientific research tests conducted in our territory are normal," the ministry said in the statement. "These tests are not targeted at any country and at any specific goals."

U.S. officials have told Congress the initial use of the new hypersonic glider will be for delivering nuclear warheads through what China believes will be a future global U.S. missile defense shield directed against its missiles.

The most advanced hypersonic missile is the DF-ZF glider that is launched atop a ballistic missile and then glides to its target in near space. The glider is capable of maneuvering at speeds of between Mach 5 and Mach 10—3,836 miles per hour and 7,672 miles per hour, respectively.

Such high speeds require special materials and electronics capable of withstanding the high temperatures and pressures created by those velocities.

The Oct. 8 broadcast reported on China's development of a hypersonic wind tunnel that is used for testing the high-speed strike vehicles. The test system is located in Beijing and is known as the JF12 shock wave wind tunnel. A technician from the Chinese Academy of Sciences, Jiang Zonglin, told CCTV the tunnel is comparable to an unspecified "renowned" U.S. wind tunnel.

Jiang said the JF12 "has reached the world's advanced level" and is capable of revealing many issues U.S. researchers have yet to discover about hypersonic flight.

According to Jiang, tests at the JF12 are conducted every two days and the facility will be operating at full capacity through the end of the year.

China expects to increase the speed of next generation hypersonic vehicles past the current Mach 5 limit, the report said.

The broadcast showed three hypersonic vehicles over various shapes, including a triangular-shaped glider, and one weapon that appeared similar in shape to the last stage of a ballistic missile.

The report also included images of the JF12 that stated the tunnel creates wind speeds of between Mach 5 and Mach 10 and uses a nozzle diameter of 8.2 feet. The test duration is 100 milliseconds.

The Pentagon's 2013 annual report on the Chinese military mentioned the JF12 wind tunnel as a development of the China Academy of Sciences' Institute of Mechanics.

The Institute announced in May 2012 that it began hypersonic testing of the super-large wind tunnel that China claimed is the largest in the world.

Air Force Gen. John Hyten, commander of the Strategic Command, said in July he is worried about the development of hypersonic missiles by China and Russia. The United States is also pursuing the weaponry, he said.

"Hypersonic technology is concerning to me, but it's really no more concerning to me than any cruise missile technology, any ballistic missile technology," Hyten said. "We have to be prepared to defend ourselves against all those threats. And we have to have a deterrent that is ready to respond in case any of those break out."

The National Air and Space Intelligence Center stated in a report made public last summer that hypersonic glide vehicles are a new class of weapons and an emerging threat. Hypersonic missiles "are maneuverable vehicles that travel at hypersonic (greater than Mach 5) speed and spend most of their flight at much lower altitudes than a typical ballistic missile," the report said. "The combination of high speed, maneuverability, and relatively low altitude makes them challenging targets for missile defense systems," the report added, noting they are currently being developed by Russia and China.

Congress last year passed legislation requiring the Pentagon's Missile Defense Agency to create a dedicated program aimed at countering hypersonic missile threats.

An Air Force-sponsored study warned last year that the United States is falling behind in the emerging hypersonic arms race.

"The People's Republic of China and the Russian Federation are already flight-testing high-speed maneuvering weapons that may endanger both forward-deployed U.S. forces and even the continental United States," the study said. "These weapons appear to operate in regimes of speed and altitude, with maneuverability that could frustrate existing missile defense constructs and weapon capabilities."

The growing threat of hypersonic arms is said by U.S. officials to be part of two major Pentagon studies that are nearing completion. One is the nuclear posture review that will include an examination of strategic threats to the United States posed by hypersonic nuclear delivery vehicles. A second is a review of strategic missile defenses that are being challenged by new hypersonic and other maneuvering missiles.

Rick Fisher, a China weapons expert with the International Assessment and Strategy Center, said the Chinese television broadcast confirms reports about the new high-technology weapons development.

"This CCTV show provides additional validation that China is developing hypersonic maneuverable reentry vehicles (MaRVs) that some PLA experts suggest in the future may also be launched from PLA navy ships to attack U.S. Navy ships."

"The delta shape may be a generic test model or it could indicate the shape of an early PLA MaRV warhead."

China's development of high-speed maneuvering warheads is a high threat because "this type of warhead is much more difficult to intercept with current U.S. missile defenses," Fisher said.

Three years ago, Lee Fuell, an intelligence analyst with the National Air and Space Intelligence Center, told Congress China's hypersonic glider appears designed for nuclear weapons.

"At this point, we think that's associated with their nuclear deterrent forces," Fuell said. "Of great concern would be if they were to apply the same technology and capability with a conventional warhead or even just without a warhead because of the kinetic energy that it has."

In addition to an unpowered glider, China also is developing a scramjet-powered hypersonic missile. A Chinese technical publication reported in May that a breakthrough was made in development of a ramjet engine for hypersonic missiles.

The CCTV broadcast on the hypersonic missiles was first reported by the online newsletter "The War Zone" on Tuesday.