Washington, Apr 6 (IANS): The US has revealed about a recent test of a hypersonic weapon that took place in mid-March and was kept a secret for two weeks to "avoid escalating tensions with Russia", CNN reported, citing a US defence official familiar with the matter.

The Defence Advanced Research Projects Agency (DARPA) -- the Pentagon's research and development branch -- said on Tuesday that they completed a free flight test of the Hypersonic Air-breathing Weapon Concept (HAWC).

This is the second successful flight in the DARPA's HAWC programme. Last September, a different vehicle configuration from another contractor team also reached hypersonic flight, Xinhua news agency reported citing CNN.

The HAWC is a cooperation programme between the DARPA and US Air Force to develop air-launched hypersonic cruise missiles.

Air-breathing vehicles utilise air captured from the atmosphere to achieve sustained propulsion.

The speed and maneuverability of such hypersonic cruise missiles allow both evasion of defences and quick strikes.

In the defence budget for the fiscal year 2023, the White House asked for $7.2 billion for developing and fielding long range fires, including hypersonic missiles.

A US government agency has identified 70 efforts related to the development of hypersonic weapons, expected to cost nearly $15 billion between 2015 and 2024.