Russia fired an upgraded version of its Iskander short-range ballistic missile for the first time in a summer strike on the Ukrainian capital city, the country's military intelligence agency shared this week.

Russian forces have significantly ramped up their ballistic missile attacks on Ukraine this year. These strikes come as Russia upgrades its arsenal and Ukraine struggles to procure sufficient numbers of critical air-defense interceptors.

On Thursday, Ukraine's GUR, the country's military and defense intelligence agency, said that Russia had used an upgraded ballistic missile, the 9M723-2 or "Iskander-1000," against Ukraine for the first time during a complex bombardment of Kyiv this summer.

The Iskander-1000 is an upgraded variant of the 9M723-1, a ballistic missile fired by Russia's Iskander system, with a larger engine and launcher that extend its range. Ukraine has assessed that these modifications have increased its maximum range to about 340 miles, about 100 miles farther than its predecessor. It added that most other components remain the same.

The first combat use of the Iskander-1000 highlights Russia's ongoing investments in expanding and improving its ballistic missile arsenal. Ukrainian officials have said such weapons are becoming an increasingly prominent part of Moscow's strike campaign. The additional range on the upgraded 9M723-2 missile allows Russian Iskander launchers to operate from farther back while still threatening Kyiv and other Ukrainian cities.

Ukraine has tracked evolutions in Russian ballistic missile technology, including changes in maneuverability that make the weapons more difficult to intercept. These developments have at times challenged Ukrainian air defenses, such as the US-made MIM-104 Patriot surface-to-air missile system.

Last fall, for instance, a US defense intelligence assessment found that Ukraine's Patriots struggled to consistently intercept Russian ballistic missiles due to certain recent "tactical improvements" Moscow had made to the weapons.

The Patriot is a top-tier air defense platform in Ukraine and is considered its best defense against Russian ballistic missiles like the Iskander and the air-launched Kh-47M2 Kinzhal, but it's not infallible. Right now, though, Ukraine is running low on interceptor missiles. Some nights, Ukraine hasn't been able to intercept a single missile.

Russia has also expanded its arsenal with assistance from North Korea. Earlier this month, the Ukrainian Air Force said North Korea's KN-23 missile, which is a rough copy of Russia's Iskander missile, had been used in two strikes. Ukrainian and Western officials have assessed that ongoing military cooperation between North Korea and Russia has allowed both countries to improve their weapons and technologies.