The US military is working on a new air-to-air missile to replace the Raytheon AIM-120D AMRAAM, according to a report in Popular Mechanics.

The development of the weapon, which is said to have capabilities to destroy targets beyond visual range, has come to light after FlightGlobal found a long-range engagement weapon (LREW) programme listed in US budget documents released in March.

Launched two years ago, the LREW project aims to maintain the the country's dominance in air combat. The design analysis, engineering and kill chain requirement for the weapon was expected to be completed last year. However, the results have not been made public yet.

"When successful, LREW will transition to multiple services," the documents read.

The website noted that the existence of this particular LREW went unnoticed until now since it was mentioned under the "emerging capabilities technology development" head, which is a category usually used for small electronic warfare projects.

The existence of this project is the first sign that suggests a major replacement for the AIM-120 AMRAAM (Advanced Medium Range Air-to-Air Missile) is being developed.

The US military introduced these missiles in the early 1980s and has been advancing their capabilities over the years, with the latest version, AIM-120D AMRAAM – developed by Raytheon – offering an approximate range of 100 miles and features like GPS guidance, high-angle boresight and two-way datalink.

The new missile is likely to extend that range and also bring in all those capabilities that the AIM-120D AMRAAM could not manage to include. For instance, it could have an advanced electronically scanned array (AESA) radar for stealth operations or could use ramjets in order to achieve speeds around or over Mach 5.