The United States military tested a hypersonic missile last month but decided to keep it quiet for two weeks in order to avoid ramping up tensions further with Russia.
The mid-march test came just as President Joe Biden was set to travel to Europe to discuss Russia's ongoing invasion of Ukraine, CNN reported, though scant details have been released about the situation.
The test was conducted off the west coast with the missile, a Hypersonic Air-breathing Weapon Concept (HAWC), launched from a B-52 bomber.
US military successfully tested hypersonic missiles but kept the project secret to avoid escalating tensions https://t.co/i5ZzNPrEvX
— Daily Mail Online (@MailOnline) April 5, 2022
The missile's booster engines first push the weapon up to a high speed before the air-breathing scramjet engine kicks in, pushing the missile to hypersonic speeds of Mach 5 and faster, according to the Defense Advanced Research Projects Agency.
The missile flew at heights greater than 65,000 feet for 300 miles - which would have taken around five minutes -though officials provided few details about the flight.
DARPA said the test met all of its objectives, including the missile's integration and release, safe separation from the launch aircraft, booster firing, and cruise.
The test came at a time when tensions between Russia and U.S. are heightened due to the country's ongoing invasion of Ukraine, and just days after Russia used its own hypersonic missiles on an ammunition warehouse in western Ukraine.
US officials recently downplayed the Russia's use of their own hypersonic Kinzhal missile which is essentially an air-launched version of a Russian Iskander short-range ballistic missile and not new hypersonic weaponry.
The US test involved the use of a powerful engine, called an air-breathing scramjet.
The HAWC missile does not contain a warhead - but relies instead on sheer kinetic energy to destroy targets.
The US has been looking at hypersonic weapons with renewed emphasis after successful tests were conducted by China and Russia, furthering concerns that the US is lagging in developing latest military technology.
China is thought to have successfully tested a hypersonic glide vehicle over the summer, while Russia has tested its submarine-launched hypersonic missile, known as the Tsirkon.
Hypersonic missiles are dropped from bomber jets and can travel up to 15 times faster than the speed of sound. They can also be steered in-flight toward a target, making them more precise and harder to shoot down.
The development of hypersonic missiles has led to an arms race between the US, China and Russia.
Last year, General David Thompson, the US Space Force's vice-chief of space operations, stated that the US was 'not as advanced' as China or Russia in hypersonic weapons.
He said: 'We have catching up to do very quickly. The Chinese have had an incredibly aggressive hypersonic program for several years.'
The US has been careful throughout the Ukraine conflict to avoid taking steps that might further escalate tensions between Russia and the US, including opposing the introduction of a no-fly zone above the country and disallowing the Polish Air Force to allow its fighter jets to be flown by Ukrainians.
US does have hypersonic missiles but never used them and Russia already used them long ago https://t.co/Ba3p0aOrmI
— Conflict Radar 5 (@ConflictRadar5) April 5, 2022
The US has also opposed the transfer of fighter aircraft to Ukraine through the United States, concerned that the Kremlin could interpret such a move as the US and NATO entering the conflict in Ukraine.
The details of this hypersonic test were kept under wraps for two weeks in the hopes of avoiding any kind further provocation of Russian President Vladimir Putin as his troops continue to blast Ukraine.
Russia, meanwhile, used its Kinzhal hypersonic missiles for the first time in Ukraine last month, destroying a weapons storage site.
Russia has never before admitted using the high-precision weapon in combat, and state news agency RIA Novosti said it was the first use of the Kinzhal hypersonic weapons during the conflict in pro-Western Ukraine.
Moscow claims the 'Kinzhal'- or Dagger - is 'unstoppable' by current Western weapons. The missile, which has a range of 1,250 miles, is nuclear capable.
'The Kinzhal aviation missile system with hypersonic aeroballistic missiles destroyed a large underground warehouse containing missiles and aviation ammunition in the village of Deliatyn in the Ivano-Frankivsk region', the Russian defence ministry said Saturday.
Russian Maj. Gen. Igor Konashenkov also said that the Russian forces used the anti-ship missile system Bastion to strike Ukrainian military facilities near the Black Sea port of Odesa.
Aerial footage released by the Russian military claimed to show the missile strike. Large, long buildings are shown in the footage in a snowy region, before one is obliterated by a huge explosion - sending flames, earth and debris high into the air. People can be seen on the ground fleeing as smoke pours from the site.
Russia reportedly first used the weapon during its military campaign in Syria in 2016 to support the Assad regime, although it was unclear if this was the same model. Some of the most intense bombing came in 2016 during the battle for Aleppo, resulting in hundreds of civilian deaths.
Russian President Vladimir Putin has termed the missile 'an ideal weapon' that flies at 10 times the speed of sound and can overcome air-defense systems.
