Almost three months after Russia shocked the world by invading Ukraine, its military faces a bogged-down war, the prospect of a bigger NATO, and an opponent buoyed Sunday by wins on and off the battlefield.

Top diplomats from NATO met in Berlin with the alliance’s chief, who declared that the war “is not going as Moscow had planned.”

“Ukraine can win this war,” NATO Secretary-General Jens Stoltenberg said, adding that the alliance must continue to offer military support to Kyiv. He spoke by video link to the meeting as he recovers from a COVID-19 infection.

On the diplomatic front, both Finland and Sweden took steps bringing them closer to NATO membership despite Russian objections. Finland announced Sunday that it was seeking to join NATO, saying the invasion had changed Europe’s security landscape. Several hours later, Sweden’s governing party endorsed the country’s own bid for membership, which could lead to an application in days.

If the two nonaligned Nordic nations become part of the alliance, it would represent an affront to Russian President Vladimir Putin, who has called NATO’s post-Cold War expansion in Eastern Europe as a threat to Russia. NATO says it is a purely defensive alliance.

While Moscow lost ground on the diplomatic front, Russian forces also failed to make territorial gains in eastern Ukraine.

Ukraine said it held off Russian offensives in the east, and Western military officials said the campaign Moscow launched there after its forces failed to seize the capital, Kyiv, has slowed to a snail’s pace.

Ukraine, meanwhile, celebrated a morale-boosting victory 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 anthem among Ukrainians during the war.

President Volodymyr Zelenskyy vowed that 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 received special permission to go to Italy to represent Ukraine in the contest.

They will return to a country still fighting for survival.

Russian and Ukrainian fighters are engaged in a grinding battle for Ukraine’s eastern industrial heartland, the Donbas. Ukraine’s most experienced and best-equipped soldiers have fought Moscow-backed separatists there for eight years.

Even with its setbacks, Russia continues to inflict death and destruction across Ukraine. Over the weekend, its forces hit a chemical plant and 11 high-rise buildings in Siverodonetsk, in the Donbas, the regional governor said. Gov. Serhii Haidaii said two people were killed in the shelling and warned residents still in the city to stay in underground shelters.

Russian missiles destroyed “military infrastructure facilities” in the Yavoriv district of western Ukraine, near the border with Poland, the governor of the Lviv region said. Lviv is a major gateway for the Western-supplied weapons Ukraine has acquired during the war.

The Ukrainian military said it held off a renewed Russian offensive in the Donetsk area of the Donbas. Russian troops also tried to advance near the eastern city of Izyum, but Ukrainian forces stopped them, the governor of Ukraine’s Kharkiv region, Oleh Sinegubov, reported.

And Ukraine 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. It posted a video of exploding bridges on Facebook. The command also said it destroyed Russian communication lines in the area to prevent Russia from bringing in more troops to attack the towns of Lisichansk and Severodonetsk, it said.

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 on Twitter.

The assessments of Russia’s war performance came as Russian troops retreated from around Kharkiv, Ukraine’s second-largest city, which was a key military objective earlier in the war and was bombarded for weeks. The regional governor said there had been no shelling in the city for several days, though Russia continued to strike the wider Kharkiv region.

One Ukrainian battalion that had been fighting in the region reached the border with Russia on Sunday and made a victorious video there addressed to Zelenskyy.

In the video posted on Facebook by Ukraine’s Ministry of Defense, a dozen fighters stood around a blue-and-yellow post, Ukraine’s colors.

One explained that 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.

Despite the continuing threat of missile attacks, many people were returning home to Kharkiv and other cities around Ukraine, said Anna Malyar, deputy head of the Ministry of Defense, on Sunday. 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,” she 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 who have refused to surrender and remain holed up in the Azovstal steel factory.

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 suffered severe food, water and medicine shortages; untreated injuries were sometimes leading to sepsis.

The Ukrainian prosecutor-general’s office said regional prosecutors have launched a criminal investigation into Moscow’s alleged use of restricted incendiary bombs at the steelworks. International law allows certain use of incendiary munitions but bars their use to directly target enemy personnel or civilians.

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

The invasion of Ukraine has other countries along Russia’s flank worried they could be next, including Finland, which shares both a 1,340-kilometer (830-mile) 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.”

In Sweden, after the ruling Social Democratic Party on Sunday backed plans to join NATO, the plan was to be discussed Monday in parliament, with an announcement by the Cabinet to follow.

However, NATO operates by consensus, and the Nordic nations’ potential bids were thrown into question over concerns from Turkey. Turkish Foreign Minister Mevlut Cavusoglu said he had discussed Turkey’s concerns at the NATO meeting, especially Sweden and Finland’s alleged support for Kurdish rebel groups and their restrictions on weapons sales to Turkey.

But during a Sunday visit to Sweden, 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 of GOP senators to the region. They made a surprise visit to Kyiv on Saturday in a show of support.