Ukraine has lost over 40% of the territory in Russia's Kursk region that it seized in a surprise incursion in August as Russian forces have mounted waves of counter-assaults, a senior Ukrainian military source said.

KYIV, Ukraine >> Ukraine has lost over 40% of the territory in Russia’s Kursk region that it seized in a surprise incursion in August as Russian forces have mounted waves of counterassaults, a senior Ukrainian military source said.

The Ukrainian source revealed that their forces initially controlled up to 1,376 square kilometres (531 square miles) of territory in Kursk but now hold around 800 square kilometres (309 square miles).

Ukraine has lost over 40 per cent of the territory it previously gained in Russia's Kursk Oblast due to Russian counterattacks, Reuters reported on Nov. 23, citing a source in Ukraine's General Staff.

Ukraine has now lost more than 40% of the territory of Kursk Oblast, which it has controlled since August, as a result of Russian counterattacks, says a Reuters source in the General Staff of the Ukrainian Armed Forces.

Ukraine has lost over 40 percent of the territory in Russia's Kursk region that it rapidly seized in a surprise incursion in August as Russian forces have mounted waves of counterassaults, a senior Ukrainian military source has said.

Meanwhile, Ukraine's surprise incursion into Russia's Kursk region is faltering. Russian troops have pushed Kyiv's offensive backwards. Experts have questioned the success of the offensive, with one calling it a "strategic catastrophe" given manpower shortages faced by Ukraine.

The move marks the latest reversal from the White House on what weapons it’s sending and how freely Ukraine can use them.

Russia reportedly provided North Korea with oil, anti-air missiles and economic help in exchange for troops to support Moscow's war on Ukraine.