Ukrainian President Volodymyr Zelensky has hailed Ukraine's "good advance" in Russia's Kursk region, saying Kyiv was achieving its strategic goal in the operation.
"Today we have advanced well in the Kursk region. We are achieving our strategic goal," Mr Zelensky said in his evening address, published on Telegram.
Mr Zelensky also appealed to partners to allow long-range strikes on targets inside Russia.
"The bolder the partners' decisions, the less Putin can do," he said.
Earlier, Ukrainian Deputy Prime Minister Iryna Vereshchuk said Ukraine will allow the evacuation of civilians from Russia's Kursk region into Russia and Ukraine and admit international humanitarian organisations to the area where its troops have launched a major offensive.
"Our military forces plan to... open humanitarian corridors for the evacuation of civilians: both in the direction of Russia and of Ukraine," she said.
Ukraine was also planning to create a "buffer zone" in the Kursk region, to prevent Russia shelling its territory from there.
"The creation of a buffer zone in the Kursk region is a step to protect our border communities from daily hostile shelling," Ukrainian Interior Minister Igor Klymenko said on Telegram.
Mr Zelensky said earlier that Kyiv's forces were continuing to advance in Russia's Kursk region and that they had moved forward 1-2km in various directions since the start of the day.
In a video posted on his Telegram account, Mr Zelensky was shown speaking by video link with his top commander, Oleksandr Syrskyi, who said Ukrainian forces had captured 100 Russian prisoners of war during the cross-border incursion today.
Thousands of Ukrainian troops rammed through the Russian border in the early hours of 6 August into Russia's western Kursk region in what President Vladimir Putin said was a major provocation that was aimed at gaining a stronger hand in possible future ceasefire talks.
In an embarrassment for Russia, Ukraine carved out a slice of Kursk and though Mr Putin said the Russian army would push out the Ukrainian troops, intense battles have so far failed to expel them.
"The situation still remains difficult," said Yuri Podolyaka, an influential Ukrainian-born, pro-Russian military blogger.
"The enemy still has the initiative, and so, albeit slowly, it is increasing its presence in the Kursk region," he said.
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
Russia said that it had destroyed 117 Ukrainian drones in Russia overnight, mostly in the Kursk, Voronezh and Belgorod and Nizhny Novgorod regions.
It said missiles had also been shot down and showed Sukhoi Su-34 bombers pounding Ukrainian positions in Kursk.
Russian commanders had said that the front in Kursk had stabilised, though Mr Zelensky said his forces were continuing to advance there and ordered his generals to develop the next "key steps" in the operation.
US President Joe Biden said US officials are in constant touch with Ukraine over the invasion of Russia, which he said had "created a real dilemma" for Mr Putin, who ordered thousands of troops into Ukraine in 2022.
The White House said Ukraine did not provide advance notice of its incursion and the United States had no involvement in the operation, though Russian officials have suggested Ukraine's Western backers must have known of the attack.
A US official said the goal of the Kursk incursion appeared to be to force Russia to pull troops out of Ukraine to defend Russian territory against the cross-border assault.
The Ukrainian assault on Russia, the biggest by a foreign force since World War II, has dramatically changed the narrative around the war.
Russia had been advancing since the failure of Ukraine's 2023 counter-offensive to make any major gains against Moscow's forces.
President Putin said on Monday that Ukraine "with the help of its western masters" was aiming to improve Kyiv's negotiating position ahead of possible peace talks and to slow the advance of Russian forces.
But in a sign the attack is hardening the Kremlin's position, Mr Putin questioned what negotiations there could be with an enemy he accused of firing indiscriminately at Russian civilians and nuclear facilities.
Russian officials say Ukraine is trying to show its western backers that it can still muster major military operations just as pressure mounts on both countries to agree to talk about halting the war.
By bringing the war to Russia, Ukraine has forced nearly 200,000 Russians to evacuate border regions.
Governor of Russia's border region of Belgorod Vyacheslav Gladkov declared a regionwide state of emergency, citing continued attacks by Ukrainian forces.
Read more:
Latest Ukraine stories
"The situation in the Belgorod region continues to be extremely difficult and tense," Mr Gladkov said in a video posted on the Telegram messaging app.
Daily shelling by the Ukrainian armed forces had destroyed houses, killing and wounding civilians, he added.
Ukraine has claimed it controls at least 1,000sq/km of Russia, more than double what Moscow's figures indicate.
Reuters was not able to independently verify the battlefield situation.
A Russian military blogger close to the defence ministry who goes by the name "Rybar" said on Telegram that Ukrainian forces were attacking in several areas at once.
Russian troops were "pinning down" Kyiv soldiers, striking their armoury, while reinforcements were arriving.
