Ukrainian forces have launched a new counter-offensive against Russian troops in the country's southern Kherson region.

Media outlets in Ukraine reported on Monday that Ukrainian troops had breached the first line of Russian defenses and forced part of the Russian forces to retreat from their positions in Kherson.

A spokesperson for the Ukrainian military told reporters that recent strikes on Russia's southern logistical routes had been unquestionably effective, and that more than 10 Russian ammunition dumps had been hit over the last week.

But she declined to offer more details on the new offensive, citing the need for secrecy.

Meanwhile, Russia's defense ministry said on Monday that Ukraine troops had suffered heavy losses in an unsuccessful offensive in the Kherson and other regions.

The ministry also said Ukrainian tanks and warplanes had been destroyed, and that more than 560 Ukrainian military personnel had died.

Russian troops deployed in Crimea, south of Kherson, have been hit by a recent spate of blasts and assaults on their facilities since early August. Russia unilaterally annexed Crimea eight years ago.

Ukraine's government intends to intensify its counter-attacks in the south to retake control of the territory, while pushing back Russians in the Donbas region in the east with weapons supplied by the West.