Ukrainian President Volodymyr Zelenskyy said Sunday the daring military incursion into Russia’s Kursk region aims to create a buffer zone to prevent further attacks by Moscow across the border.

It was the first time Zelenskyy clearly stated the aim of the operation, which was launched on Aug. 6. Previously, he had said the operation aimed to protect communities in the bordering Sumy region from constant shelling.

Zelenskyy said “it is now our primary task in defensive operations overall: to destroy as much Russian war potential as possible and conduct maximum counteroffensive actions. This includes creating a buffer zone on the aggressor’s territory -– our operation in the Kursk region,” he said in his nightly address.

This weekend, Ukraine destroyed a key bridge in the region and struck a second one nearby, disrupting supply lines as it pressed a stunning cross-border incursion that began Aug. 6, officials said.

Pro-Kremlin military bloggers acknowledged the destruction of the first bridge on the Seim River near the town of Glushkovo will impede deliveries of supplies to Russian forces repelling Ukraine’s incursion, although Moscow could still use pontoons and smaller bridges. Ukraine’s air force chief, Lt. Gen. Mykola Oleshchuk, on Friday released a video of an airstrike that cut the bridge in two.

Less than two days later, Ukrainian troops hit a second bridge in Russia, according to Oleshchuk and Russian regional Gov. Alexei Smirnov.

As of Sunday morning, there were no officials giving the exact location of the second bridge attack. But Russian Telegram channels claimed that a second bridge over the Seim, in the village of Zvannoe, had been struck.

According to Russia’s Mash news site, the attacks left only one intact bridge in the area. The Associated Press could not immediately verify these claims. If confirmed, the Ukrainian strikes would further complicate Moscow's attempts to replenish its forces and evacuate civilians.

Glushkovo is about 12 kilometers (7.5 miles) north of the Ukrainian border, and approximately 16 kilometers (10 miles) northwest of the main battle zone in Kursk. Zvannoe is located another 8 kilometers (5 miles) to the northwest.

Kyiv previously has said little about the goals of its push into Russia with tanks and other armored vehicles, the largest attack on the country since World War II, which took the Kremlin by surprise and saw scores of villages and hundreds of prisoners fall into Ukrainian hands.

The Ukrainians drove deep into the region in several directions, facing little resistance and sowing chaos and panic as tens of thousands of civilians fled. Ukraine’s Commander in Chief, Gen. Oleksandr Syrskyi, claimed last week that his forces had advanced across 1,000 square kilometers (390 square miles) of the region, although it was not possible to independently verify what Ukrainian forces effectively control.

Buffer zones sought by both sides

In his remarks on creating a buffer zone, Zelenskyy said Ukrainian forces “achieved good and much-needed results.”

Analysts say that although Ukraine could try to consolidate its gains inside Russia, it would be risky, given Kyiv’s limited resources, because its own supply lines extending deep into Kursk would be vulnerable.

The incursion has proven Ukraine's ability to seize the initiative and has boosted its morale, which was sapped by a failed counteroffensive last summer and months of grinding Russian gains in the eastern Donbas region.

For his part, Russian President Vladimir Putin said while visiting China in May that Moscow’s offensive that month in Ukraine’s northeastern Kharkiv region was aimed at creating a buffer zone there.

That offensive opened a new front and displaced thousands of Ukrainians. The attacks were a response to Ukrainian shelling of Russia’s Belgorod region, Putin said.

“I have said publicly that if it continues, we will be forced to create a security zone, a sanitary zone,” he said. “That’s what we are doing.”

Ukraine’s move into Kursk resembled its lightning operation from September 2022, led by Syrskyi, in which its forces reclaimed control of the northeastern Kharkiv region after taking advantage of Russian manpower shortages and a lack of field fortifications.

Zelenskyy seeks permission to strike deeper into Russia

On Saturday, Zelenskyy urged Kyiv’s allies to lift remaining restrictions on using Western weapons to attack targets deeper in Russia, including in Kursk, saying his troops could deprive Moscow “of any ability to advance and cause destruction” if granted sufficient long-range capabilities.

“It is crucial that our partners remove barriers that hinder us from weakening Russian positions in the way this war demands. … The bravery of our soldiers and the resilience of our combat brigades compensate for the lack of essential decisions from our partners,” Zelenskyy said on the social platform X.

Russia's Foreign Ministry and pro-Kremlin bloggers alleged U.S.-made HIMARS launchers have been used to destroy bridges on the Seim. These claims could not be independently verified.

Ukraine’s leaders have repeatedly sought authorization for long-range strikes on Russian air bases and other infrastructure used to pummel Ukraine’s energy facilities and other civilian targets, including with retrofitted Soviet-era “glide bombs” attacking Ukraine’s industrial east in recent months.

Moscow also appears to have increased attacks on Kyiv, targeting it Sunday with ballistic missiles for a third time this month, according to the head of the municipal military administration. Serhii Popko said in a Telegram post the “almost identical” August strikes on the capital “most likely used” North Korean-supplied KN-23 missiles.

Another attempt to target Kyiv followed at about 7 a.m. Popko said, this time with Iskander cruise missiles. Ukrainian air defenses struck down all the missiles fired in both attacks on the city, he said.

Fears mount for Zaporizhzhia nuclear plant

Elsewhere, the head of the U.N. nuclear watchdog agency said Saturday the safety situation at the Russian-occupied Zaporizhzhia Nuclear Power Plant is deteriorating.

International Atomic Energy Agency head Rafael Grossi urged “maximum restraint from all sides” after an IAEA team at the plant reported an explosive carried by a drone detonated just outside its protected area.

According to Grossi, the impact was “close to the essential water sprinkle ponds” and about 100 meters (100 yards) from the only power line supplying the plant. The IAEA team at the plant has reported intense military activity in the surrounding area in the past week, it said.

Kyiv and Moscow have traded blame for attacks near the power plant since it was captured by Russian forces early in the 2022 invasion, including a fire at the facility last weekend. Grossi said the blaze had caused “considerable damage,” but posed no immediate danger to nuclear safety.

Belarus says it's deploying more troops on Ukraine border

Russian ally Belarus has massed “nearly a third” of its army along its border with Ukraine, according to authoritarian President Alexander Lukashenko.

Lukashenko told Russian state TV that Minsk was responding to the deployment of more than 120,000 Ukrainian troops to the 1,084-kilometer (674 mile) frontier. Belarus’ professional army numbers upward of 60,000.

Ukrainian border force spokesman Andrii Demchenko said Sunday it had not observed any sign of a Belarusian buildup.

Lukashenko, in power for three decades, has relied on Russian support to suppress the biggest protests in Belarus’ post-Soviet history after his 2020 reelection, widely seen as a sham both at home and abroad. He allowed Russian troops to use Belarus’ territory to invade Ukraine and let Moscow deploy some tactical nuclear weapons on its soil.