We've been documenting how more and more US Patriot missile batteries have been showing up in Ukraine, as even Israel has of late openly acknowledged sending one, with more said to be on the way.

But it hasn't taken long for Russia to respond by upgrading its ballistic missile systems to evade Ukrainian air defenses, including US-supplied Patriot systems, according to a report by the Financial Times on Thursday. The report, which cites Ukrainian and US officials, details that the modifications affect both the Iskander-M short-range ballistic missiles and the air-launched Kinzhal missiles.

These have ranges of up to around 300 miles, with the upgraded missiles now said to be capable of performing sharp maneuvers or steep dives as they approach their targets, making them significantly more difficult to intercept.

One Ukrainian official admitted the development to be a "game-changer for Russia" - as cited in Financial Times. Western intel sources further conceded a noticeable drop in successful interceptions by Ukraine's air defenses as a result.

"Ukraine's ballistic missile interception rate improved over the summer, reaching 37 per cent in August, but it plummeted to 6 per cent in September, despite fewer launches, according to public Ukrainian air force data compiled by the London-based Centre for Information Resilience and analyzed by the Financial Times," the report underscores.

A notable successful Russian strike which was able to evade significant air defenses was on August 28, when a major facility for the manufacture of Turkish-made Bayraktar drones was hit, in what many analysts said at the time sent a clear message to Ankara.

And during an attack wave on September 18, Ukraine’s Air Force reported - somewhat unusually - that all four Iskander missiles launched that day bypassed Patriot defenses entirely. Such had become a 'pattern' over the summer.

These prior instances in the summer saw Ukraine's air defenses at times down merely one missile out of seven or more, and that the intercept rate was previously consistently higher.

An American Patriot surface-to-air missile lies on the streets in Kiev:

Also of note in the fresh report is the feedback that major defense makers are getting in real-time. "Ukraine shares Patriot engagement data with the Pentagon and the air defense system’s US manufacturers, said the western and Ukrainian officials," FT writes.

"Virginia-based Raytheon makes the Patriot system, while Maryland-based Lockheed Martin produces the system’s interceptor missiles," the report continues, describing that "The data is used to make updates needed to keep pace with Russia’s adjustments, but one official said those improvements often lagged behind Moscow’s evolving tactics."