President Volodymyr Zelenskyy said Ukraine had launched an incursion into Russian territory to "restore justice" and pressure Moscow's forces, in his first acknowledgement of Kyiv's surprise offensive into the western Kursk region.
Moscow's forces on Sunday were in their sixth day of intense battle against Kyiv's largest incursion into Russian territory since the start of the war, which left southwestern parts of Russia vulnerable before reinforcements started arriving.
Russian authorities rushed to evacuate residents and imposed a sweeping security regime in three border regions on Saturday, after the attack that military analysts say caught the Kremlin off-guard.