KYIV, Ukraine — Talks between Russia and Ukraine opened Monday amid skepticism that they would produce any breakthrough to halt Europe’s biggest ground war in 75 years, as Ukrainian fighters continued to fend off the capture of key cities, Russian missiles pounded targets and hundreds of thousands of people fled the country.

Delegations from Kyiv and Moscow met Monday morning at a site near Ukraine’s border with Belarus. Ukrainian President Volodymyr Zelenskyy had agreed to the negotiations Sunday, despite seeing “small chance to end the war,” and said the fate of his country as an independent nation had now entered a “crucial period.”

In Kyiv, a two-day-long curfew was lifted Monday to allow residents to venture out cautiously to replenish supplies, get some fresh air and survey the state of their city of 3 million people. Many lined up for hours outside gas stations and supermarkets, mostly ignoring the occasional wail of air-raid sirens.

Fighting continued on the outskirts of the capital, with satellite images showing Russian troops mostly massed about 19 miles north of the city, according to the British government. No major population centers have yet fallen to Russian forces, which has raised fears that Russian President Vladimir Putin will soon order an all-out blitz to overrun Ukraine, depose its government and turn it into a vassal state.

Zelenskyy once again called on his compatriots to defend their land.

“When I planned to become a president, I said that each of us is the president, because we are all responsible for our state, for our beautiful Ukraine,” Zelenskyy said in a video address Monday, the latest in a series of public messages that have buoyed and drawn the admiration of many of his people. “Now it has happened that each of us is a warrior. ... And I am confident that each of us will win.”

But half a million Ukrainians have now fled their war-torn country, said Filippo Grandi, the head of the United Nations’ refugee agency. At last count, about 281,000 people had entered Poland from Ukraine, more than 84,500 had escaped to Hungary and nearly 100,000 had arrived in Romania, Moldova and Slovakia, the agency said. The remainder had found their way to other countries.

There were signs of stress in Russia as well, with the heavy sanctions imposed by the U.S., Europe and other nations, including Japan and Australia, beginning to take a toll. The ruble plummeted in value against the dollar, the Russian central bank more than doubled interest rates, the Russian stock market did not open Monday and residents lined up at ATMs for fear of being stranded without cash.

Pessimism attended Monday’s talks, which Moscow had originally insisted be held in Belarus. Zelenskyy’s government rejected that demand, pointing out that Russian troops had used Belarus as a staging ground to invade Ukraine from the north.

Indeed, a U.S. official told the Associated Press that Belarusian troops could join their Russian counterparts on the ground in Ukraine as early as Monday. Kyiv lies barely 50 miles south of the border.

About 10 a.m. Monday, video uploaded to social media showed a pair of helicopters delivering Ukraine’s representatives to the talks in Belarus’ Gomel region, near the Ukrainian-Belarusian border. Another video showed them and their Russian interlocutors sitting at a long desk inside an ornate hall.

International discussions are also expected in New York, where the U.N. General Assembly, comprising all 193 member states of the world body, are scheduled to convene in a rare emergency session Monday morning to discuss Russia’s invasion. Russia had tried to block the meeting, but 11 of the Security Council’s 15 members voted for it.

In Geneva, the U.N.’s human rights chief, Michelle Bachelet, said her office had confirmed the deaths of 102 Ukrainian civilians — including seven children — in the war, mostly in explosions from artillery fire, rockets and airstrikes. She cautioned that the number was likely a vast undercount.

“The real figures are, I fear, considerably higher,” Bachelet told the U.N. Human Rights Council on Monday.

In his video address, Zelenskyy said 16 Ukrainian children had died. He also said more than 4,500 Russian troops had been killed since the invasion began in earnest Thursday, but independent verification has not been possible. Moscow has not issued any casualty figures.

Near the northern entrance of Kyiv, militiamen organized by the far-right Svoboda party Monday answered Zelenskyy’s call to defend their country. To justify Russia’s assault, Putin has alleged that Ukraine is ruled by “neo-Nazis” bent on committing genocide against the country’s ethnic Russians, most of whom live in the east.

Svoboda rejects accusations of fascism, saying that as nationalists their interest is to defend Ukraine, while critics of the group say that in any case it has only one seat in parliament and hardly represents the mainstream. Regardless, with Ukraine under attack, the group’s organizational and combat abilities are being put to use.

In Kyiv’s Obolon neighborhood, on a cold but sunny Monday morning, Svoboda militia members gouged out trenches in the grass-covered sidewalks, setting up machine guns on one side and a double-barreled anti-aircraft cannon on the other.

“We picked that one up from the Russians,” said Peter Kuzyk, head of Svoboda’s Kyiv branch.

On the diplomatic front, Zelenskyy praised the Western sanctions on Russia, and called on the European Union to initiate a special procedure allowing Ukraine to immediately join the 27-nation bloc.

“We are grateful to our partners for being with us, but our goal is to be with all Europeans and, most importantly, to be equal,” he said.

Such an expedited accession is extremely unlikely. But the EU has been vocal in its support for Ukraine and, in a historic first, agreed over the weekend to help arm the country in its resistance against Russian aggression.

“Another taboo has fallen, the taboo that the EU was not providing arms in a war,” Josep Borrell, the EU’s foreign policy chief, said Sunday. “Yes, we are doing it. ... This war requires our engagement in order to support the Ukrainian army.”

(By Nabih Bulos and Henry Chu, Los Angeles Times via Tribune News Service. Bulos reported from Kyiv and Chu from London.)