Russia said on Tuesday it had repelled five new attempts by Ukrainian forces to smash through its border into the Kursk region, bringing the total number of reported attacks on the border to 26 in just the past six days.

Ukraine on Aug. 6 launched the biggest foreign attack on Russia since World War Two, bursting through the border into the region of Kursk with thousands of troops supported by swarms of drones and heavy weaponry, including Western-made arms.

Russia, which sent tens of thousands of troops into Ukraine in 2022, began a major counteroffensive against the Ukrainian forces in Kursk on Sept. 10, pushing Kyiv's forces back towards the Snagost River.

But Ukrainian forces have been trying for about a week to pierce the Russian border towards Veseloe and Medvezhe in an attempt to threaten the Russian counteroffensive about 15 km (9.3 miles) to the west of the main theatre of battle in Kursk.

"With the support of army aviation and artillery fire, five attempts by the armed forces of Ukraine to pierce the border of the Russian Federation in the direction of Veseloe and Medvezhe were repelled," Russia's defence ministry said in a statement.

The ministry said that Russian forces were attacking in Lyubimovka, Malaya Loknya and a host of other settlements in Kursk.

Russian military bloggers said that Ukraine had carved out some territory towards Veseloe and Medvezhe and said Russian forces were taking back territory and storming Lyubimovka.

Reuters was unable to verify battlefield accounts from either side due to the reporting restrictions that both sides have imposed in the war zone.

Ukraine's Kursk incursion was an embarrassment for Russia's top military brass, showing the weakness of the border defences, though President Vladimir Putin says the incursion has helped Russia to accelerate its own advance in eastern Ukraine.

Russian forces have added territory in eastern Ukraine at the fastest pace in about two years, according to open-source maps and data, and Russian forces are encircling the town of Ukrainsk.

The war in Ukraine is entering its most dangerous phase to date as Ukraine asks core NATO members to give Kyiv permission to strike deep into Russia with Western missiles.