Ukraine has lost over 40% 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 counter-assaults, a senior Ukrainian military source said.

Ukraine has lost more than 40% 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 said.

Russia is now said to have prepared about 60,000 men to take Kursk back in its entirety, reportedly involving troops from North Korea.

It began with a peace move nobody wanted and ended with an experimental missile strike so rare in war Moscow gave a 30-minute heads-up to Washington.

Russian President Vladimir Putin said Thursday Russia hit a Ukrainian aerospace plant with an experimental hypersonic missile in the first use of the nuclear-capable missile against Ukraine.