Ukrainian forces have advanced further into Russia, according its President Volodymyr Zelensky.
The war-torn country’s leader used his evening address on Sunday to say troops had gone up to to three kilometres (1.86 miles) in Russia's Kursk region, taking control of two more settlements.
It came as Ukraine called on neighbouring Belarus to pull back what it described as significant levels of forces and equipment deployed at their common border.
The Ukrainian foreign ministry warned Belarus against making "tragic mistakes" while under pressure from Moscow.
A ministry statement urged the Belarus armed forces "to stop unfriendly actions" and withdraw their troops out of range of the border.
The ministry said Belarus special forces and former Wagner mercenary fighters were among the troops at the border.
Their equipment included tanks, artillery, air defence systems and engineering equipment, located in the Gomel region near Ukraine's northern border.
The statement said Ukraine "has never taken and is not going to take any unfriendly actions against the Belarusian people".
Belarusian President Alexander Lukashenko said on August 18 that Ukraine had stationed more than 120,000 troops at the border with Belarus, and deployed nearly a third of its armed forces along the entire border.
Belarus said on Monday that it sent aircraft, air defence forces and armour to its border with Ukraine.
