KYIV, Ukraine--With its military bogged down in a grinding conflict in eastern Ukraine, Russia also lost diplomatic ground over the weekend as two more European nations moved closer to joining NATO.

Finland announced Sunday that it was seeking to join the alliance, saying Russia’s invasion of Ukraine nearly three months ago had changed Europe’s security landscape. Several hours later, Sweden’s governing party endorsed a bid for membership, which could lead to an application in days.

Those moves would be a serious blow to Russian President Vladimir Putin, who has called NATO’s post-Cold War expansion in Eastern Europe a threat and cited it as a reason for attacking Ukraine. NATO says it is a purely defensive alliance.

NATO Secretary-General Jens Stoltenberg, meeting with top diplomats from the alliance in Berlin, said the war “is not going as Moscow had planned.”

“Ukraine can win this war,” he said, adding that NATO must continue to offer military support to Kyiv.

Meanwhile, Russia inflicted damage but failed to make significant territorial gains in eastern Ukraine, the focus of its war effort since its forces failed to seize the capital, Kyiv.

Russian and Ukrainian fighters are battling village-by-village for Ukraine’s eastern industrial heartland, the Donbas. Ukrainian soldiers have fought Moscow-backed separatists there for eight years.

On Sunday, a Ukrainian battalion in the Kharkiv region reached the Russian border and made a victorious video there addressed to President Volodymyr Zelenskyy. The video posted on Facebook by Ukraine’s Ministry of Defense shows a dozen fighters around a post covered with blue and yellow, Ukraine’s colors.

One said the unit went “to the dividing line with the Russian Federation, the occupying country. Mr. President, we have reached it. We are here.”

Other fighters made victory signs and raised their fists.

Determining a full picture of the fighting, especially the unfolding battle in the east, is difficult. Airstrikes and artillery barrages make it extremely dangerous for reporters to move around, and both Ukraine and the Moscow-backed separatists fighting in the east have introduced tight restrictions on reporting from the combat zone.

Over the weekend, Russian forces hit a chemical plant and 11 high-rise buildings in Siverodonetsk, in the Donbas, regional Gov. Serhii Haidaii said. Russian missiles also destroyed “military infrastructure facilities” in the Yavoriv district of western Ukraine, near the Polish border, the Lviv region’s governor said. Lviv is a gateway for Western-supplied weapons to Ukraine.

The Ukrainian military said it stopped a renewed Russian offensive in the Donetsk area of the Donbas. It also blew up two railway bridges that had been seized by Russian forces in the eastern region of Luhansk, Ukraine’s Special Operations Command said Sunday. The aim was to prevent Russia from bringing in more troops to attack the towns of Lisichansk and Severodonetsk.

And Ukrainian forces stopped an attempted Russian advance near the eastern city of Izyum, the governor of Ukraine’s Kharkiv region, Oleh Sinegubov, reported.

The Ukrainian claims could not be independently verified, but Western officials also painted a somber picture for Russia.

Britain’s Defense Ministry said in its daily intelligence update that the Russian army had lost up to one-third of the combat strength it committed to Ukraine in late February and was failing to gain any substantial territory.

“Under the current conditions, Russia is unlikely to dramatically accelerate its rate of advance over the next 30 days,” the ministry said.

Russian troops were retreating from around Kharkiv, Ukraine’s second-largest city and a key military objective earlier in the war. After weeks of bombardment and continuing strikes around the wider Kharkiv region, the regional governor said there had been no shelling in the city for several days.

Despite the continuing threat of missile attacks, many people were returning home to Kharkiv and other cities around Ukraine, Anna Malyar, deputy head of the Ministry of Defense, said.

Refugees were returning not just because of optimism that the war might ebb.

“Living somewhere just like that, not working, paying for housing, eating ... they are forced to return for financial reasons,” Malyar said in remarks carried by the RBK-Ukraine news agency.

In the southern Donbas, the Azov Sea port of Mariupol is now largely under Russian control, except for several hundred Ukrainian troops holed up in the Azovstal steel factory who have refused to surrender.

Many of their wives called on the global community to secure the release of “the entire garrison” during an online news conference. The women said the troops were suffering from a lack of food, water and medicine.

Turkey’s presidential spokesman, Ibrahim Kalin, said his country had offered to evacuate wounded Ukrainian soldiers and civilians by ship from Azovstal, the official state broadcaster TRT said.

Countries nearby worry they could be next after Russia invaded Ukraine. Finland shares a 1,340-kilometer land border and the Gulf of Finland with Russia. Putin told Finnish President Sauli Niinisto in a Saturday phone call that joining NATO would be an “error.”

Sweden’s parliament on Monday was to discuss joining NATO after the ruling Social Democratic Party endorsed a plan to do so. An announcement by the Cabinet was expected to follow.

However, NATO operates by consensus, and Turkey has cast doubts over adding Finland and Sweden as members.

During a Sunday visit to Sweden, U.S. Senate Republican leader Mitch McConnell said Finland and Sweden would be “important additions” to NATO and that the U.S. should swiftly ratify their membership. McConnell is leading a delegation to the region of GOP senators, who made a surprise visit to Kyiv on Saturday.

Ukraine celebrated a morale-boosting victory on Saturday night in the Eurovision Song Contest. The folk-rap ensemble Kalush Orchestra won the glitzy pan-European competition with its song “Stefania,” which has become a Ukrainian wartime anthem.

Zelenskyy vowed his nation would claim the customary winner’s honor of hosting the next annual competition.

“Step by step, we are forcing the occupiers to leave the Ukrainian land,” Zelenskyy said.

The band’s frontman, Oleh Psiuk, said at a news conference Sunday that the musicians were “ready to fight” when they return home. Ukraine’s government prohibits men between 18 and 60 from leaving the country, but the all-male band’s six members got special permission to go to Italy to represent Ukraine in the contest.