President Vladimir V. Putin on Sunday extended his rule over Russia until 2030, using a heavily stage-managed presidential election with no real competition to portray overwhelming public support for his domestic dominance and his invasion of Ukraine.

Some Russians tried to turn the undemocratic vote into a protest, forming long lines at polling stations at a predetermined time — noon — to register their discontent. At the same time, Ukraine sought to cast its own vote of sorts by firing a volley of exploding drones at Moscow and other targets.

But the Kremlin brushed those challenges aside and released results after the polls closed claiming that Mr. Putin had won 87 percent of the vote — an even higher number than in the four previous elections he participated in.

Afterward, Mr. Putin took a lengthy, televised victory lap, including a swaggering, after-midnight news conference at which he commented on the death of the imprisoned opposition leader Aleksei A. Navalny for the first time, referring to it as an “unfortunate incident.”

Mr. Putin is now set to use his new six-year term to further cement his control of Russian politics and to press on with the war in Ukraine. If he sees the term through to its end, he will become the longest-serving Russian leader since Catherine the Great in the 1700s.

Western governments were quick to condemn the election as undemocratic. Adrienne Watson, a spokeswoman for President Biden’s National Security Council, said “the elections were obviously not free nor fair.”

But as Mr. Putin prepares to assume a fifth term as president, he appears as emboldened as ever, deepening his confrontation with the West and showing a willingness to keep escalating tensions. Asked at the news conference whether he believed that a full-scale conflict between Russia and NATO was possible, Mr. Putin responded: “I think that anything is possible in today’s world.”

Despite the condemnation from the West, the Kremlin views these elections as a ritual crucial to Mr. Putin’s portrayal of himself as a genuinely popular leader. Analysts now expect him to elevate hard-line supporters of the war within the Russian government, betting that Western support for Ukraine will eventually crumble and Ukraine’s government forced to negotiate a peace deal on Russia’s terms.

Asked about his priorities for his next term, Mr. Putin began by referring to his invasion of Ukraine. “We need to carry out the tasks in the context of the special military operation,” he said. The results, he said, have helped “consolidate society” around his leadership, a refrain also repeated on state television.

The extent of the Russian public’s true support for Mr. Putin in the election was hard to judge, given that opposition candidates were barred from running and that ballot-stuffing and other cases of fraud were common occurrences in past Russian elections. This was also the least transparent election in recent Russian history, with the work of independent poll observers reduced to levels not seen since the collapse of the Soviet Union.

More than five million votes were reported to have come from Russian-occupied regions of Ukraine, where people were at times directed to cast their votes under the watch of armed Russian soldiers; in Ukraine’s occupied Donetsk region, Mr. Putin was reported to have received 95 percent of the vote.

In the last presidential election, in 2018, Mr. Putin’s official result was 78 percent of the vote — some 10 points lower than this weekend.

Grigorii Golosov, a political scientist in St. Petersburg, said in a phone interview that he was surprised by the high share of the vote the Kremlin claimed, describing it as “characteristic of extremely closed autocracies.”

“They can declare any results they want, given that the process is not transparent,” Mr. Golosov said. “All that these results speak to is the degree of control over the electoral system, the election process, that the Russian authorities have attained.”

For the first time in a Russian presidential election, the vote lasted for three days, from Friday to Sunday — an extended period that made it easier for the Kremlin to drive up turnout, and harder for anyone to spot fraud.

Ever since Russia’s full-scale invasion of Ukraine in February 2022, the Russian authorities have mounted a campaign of repression unseen since Soviet times, effectively criminalizing any form of antiwar speech.

And some voters interviewed in Moscow said they were proud to have voted for Mr. Putin, repeating a narrative that is a staple of Russian state television. The president, they said, had turned Russia into a prosperous, respected world power that has been forced into military conflict with a Western-armed Ukraine.

“I’m proud of my country and my president,” Irina, 59, said near a polling station on central Moscow’s Kutuzovsky Avenue, declining to give her last name when speaking to a Western reporter. “He elevated us globally to the extent that he won’t let anyone offend us.”

Ukraine repeatedly tried to undermine Mr. Putin’s image as a leader protecting Russia by launching attacks throughout the voting period.

On Sunday, Russian officials said that Ukraine had targeted seven regions of the country with exploding drones, and the Russian military said it had shot down 35 of them. An oil refinery was set on fire in the Krasnodar region of southern Russia and air defense forces shot down two drones flying toward Moscow, Russian officials said.

But there was little evidence that the assaults — which were largely ignored by state media — had succeeded in puncturing Mr. Putin’s aura among his supporters.

Pyotr, 41, a marketing specialist in Moscow, expressed pride that Mr. Putin could outwit and outlast Western adversaries. “Against the background of these under-presidents, the Macrons and so on,” he said, referring to President Emmanuel Macron of France, Mr. Putin “looks like such a celestial being.”

The other three candidates on the presidential ballot were all members of the State Duma, Russia’s rubber-stamp Parliament, and had voted for the war in Ukraine, for increased censorship and for laws curbing gay rights.

With Mr. Putin’s best-known critics in prison or in exile, one little-known opponent of the war, Boris B. Nadezhdin, did manage to collect tens of thousands of signatures in an attempt to get on the ballot. But the government invalidated enough of the signatures last month to bar him, citing what it called “irregularities.”

Still, Russia’s embattled and largely exiled opposition managed to use the elections to mount an unusual protest: Putin opponents were encouraged to line up at their polling station at noon local time on Sunday. While it was hard to judge how many voters chose that time to express their discontent, one polling station near Moscow’s famed Tretyakov Gallery was relatively quiet before a long line formed suddenly at noon.

“This is our protest — we don’t have any other options,” said Lena, 61, who came to a polling station in central Moscow before noon intending, she said, to spoil her ballot. “All of us decent people are hostages here.”

Like other voters interviewed, she declined to provide her last name, for fear of reprisal.

The noontime lines were even longer in cities with large Russian diasporas — like Belgrade, Serbia, and Yerevan, Armenia — where the Russian Embassy served as a polling station. By 1 p.m. in Berlin, the line to vote snaked for roughly a mile through the city streets, ending just past the spot where a sign marked the location of Hitler’s World War II bunker.

Yulia Navalnaya, Mr. Navalny’s widow, waited in the line for roughly six hours, making one of her first public appearances since declaring that she would carry on her husband’s political work after he died last month. She said after leaving the Russian Embassy that she had written “Navalny” on her ballot.

Ms. Navalnaya hugged and took photographs with supporters who approached her, some of them in tears.

Yulia Lozovskaya, 29, who moved to Germany from St. Petersburg after Mr. Putin’s invasion of Ukraine, said she had sought out Ms. Navalnaya after learning from social media that she was standing somewhere in the line.

“You feel you’re not alone,” Ms. Lozovskaya said, referring to the size of the crowd. “And that gives enormous strength.”