Russian troops pushed farther into a key eastern Ukrainian city and fought street by street with Kyiv's forces Monday in a battle the mayor said has left the city in ruins and driven tens of thousands of people from their homes.

Military analysts painted the fight for Sievierodonetsk as part of a race against time for the Kremlin. The city is key to Russian efforts to complete the capture of the eastern industrial region of the Donbas quickly — before more Western arms arrive to bolster Ukraine’s defense.

Weapons from the West have already helped Kyiv's forces thwart a Russian advance on the capital in the early weeks of the war. That failure forced Moscow to withdraw, regroup, and pursue the more limited objective of seizing the Donbas, where Moscow-backed separatists already held swaths of territory and have been fighting Ukrainian troops for eight years.

"The Kremlin has reckoned that it can’t afford to waste time and should use the last chance to extend the separatist-controlled territory because the arrival of Western weapons in Ukraine could make it impossible," Ukrainian military analyst Oleh Zhdanov said.

African man carries wheat

A man carries a sack of wheat flour imported from Turkey in the Hamar-Weyne market in the capital Mogadishu, Somalia Thursday, May 26, 2022. Families across Africa are paying about 45% more for wheat flour as Russia's war in Ukraine blocks exports from the Black Sea. Some countries like Somalia get more than 90% of their wheat from Russia and Ukraine. That's forcing many people to substitute wheat for other grains. But the United Nations is warning that the price hikes are coming as many parts of Africa are facing drought and hunger.  (AP Photo/Farah Abdi Warsameh)

BIDEN POINTS TO UKRAINE'S FIGHT FOR DEMOCRACY IN A MEMORIAL DAY SPEECH AT ARLINGTON

But in a potential setback for Ukraine, President Joe Biden appeared to dismiss reports that the U.S. was considering sending long-range rocket systems to the country.

In addition to pleading for weapons from allies, Ukrainian President Volodymyr Zelenskyy has also repeatedly insisted that European countries and others must punish Russia for its aggression, with sanctions and embargoes on Moscow's lucrative energy sector. In a video address Monday to European Union leaders, Zelenskyy asked the 27 nations of the bloc to target Russian oil exports, so Moscow "feels the price for what it is doing against Ukraine."

The leaders are considering an embargo on Russian oil — but struggling to find consensus.

Russia has also sought to use its energy exports to its advantage, cutting off natural gas to a handful of European countries in what was seen as an effort to punish and divide the West over its support for Ukraine. In its latest move, Russian state gas giant Gazrpom said it will halt gas supplies to Dutch gas trader GasTerra starting Tuesday. 

French Foreign Minister visits Bucha Church

French Foreign Minister Catherine Colonna visits Bucha's church, on the outskirts of Kyiv, Ukraine, Monday, May 30, 2022.  (AP Photo/Natacha Pisarenko)

The Russian military's focus on Sievierodonetsk has already left the city "completely ruined," Mayor Oleksandr Striuk said. Artillery barrages have destroyed critical infrastructure and damaged 90% of the buildings, and power and communications have been largely cut to a city that was once home to 100,000 people.

"The number of victims is rising every hour, but we are unable to count the dead and the wounded amid the street fighting," Striuk told The Associated Press in a phone interview, adding that Moscow’s troops advanced a few more blocks toward the city center.

He said that only about 12,000 to 13,000 residents remain, sheltering in basements and bunkers to escape the Russian bombardment — a situation that recalls the siege of Mariupol that trapped residents and led to some of the worst suffering of the war.

Child stands next to damaged car

A child standing next to a damaged car looks up at a building destroyed during attacks in Irpin, on the outskirts Kyiv, Ukraine, Monday, May 30, 2022.  (AP Photo/Natacha Pisarenko)

Striuk estimated that 1,500 civilians have died in his city since the war began, from Russian attacks as well as from the dire conditions, including a lack of medicine or medical treatment. More than 20,000 are feared dead in Mariupol.

A 32-year-old French journalist, Frédéric Leclerc-Imhoff, died Monday near Sievierodonetsk when he was hit by shrapnel from shelling while covering Ukrainians evacuating the area, according to his employer, French broadcaster BFM TV.

Beyond long sieges of cities, Russia's troops have also been accused of carrying out targeted killings and other atrocities in areas they briefly held around Kyiv early in the war. On Monday, prosecutors submitted the first rape case of the war to a court — the last step before a trial begins. The 31-year-old Russian soldier, who is accused of killing a man and raping his wife in Bohdanivka, a village northeast of Kyiv, will be tried in absentia, officials said.

President of European Commission speaks to media

Ursula von der Leyen, President of the European Commission, speaks to media prior the extraordinary meeting of EU leaders to discuss Ukraine, energy and food security at the Europa building in Brussels, Monday, May 30, 2022. European Union leaders will gather Monday in a fresh show of solidarity with Ukraine but divisions over whether to target Russian oil in a new series of sanctions are exposing the limits of how far the bloc can go to help the war-torn country.  (AP Photo/Geert Vanden Wijngaert)

Meanwhile, the Ukrainian military said Russian forces reinforced their positions on the northeastern and southeastern outskirts of Sievierodonetsk, 145 kilometers (90 miles) south of the Russian border in an area that is the last pocket of Ukrainian government control in Luhansk.

Luhansk Gov. Serhiy Haidai said the Russians were also pushing toward nearby Lysychansk. In addition to the journalist, two civilians were killed in the latest Russian shelling, he said.

Three civilians were also killed Monday in the Donetsk region, which together with Luhansk makes up the Donbas, the governor said. Authorities in Kharkiv reported one dead in the latest shelling of Ukraine’s second-largest city.

The Russian advance in Sievierodonetsk and Lysychansk on either side of the strategically important Siverskiy Donetsk River is part of an all-out push, Zhdanov said. 

Ukrainian Tanks move into Donetsk

Ukrainian tanks move in Donetsk region, eastern Ukraine, Monday, May 30, 2022.  (AP Photo/Francisco Seco)

The intensity of the latest fighting and the fact that Russia has poured troops in from their far east have come as a surprise to the Ukrainians, who are trying to hold out until more weapons can arrive, Zhdanov said.

On Monday, Biden told reporters that there are no plans for the U.S. to send long-range rocket systems to Ukraine, amid reports that the move is being considered.

BIDEN SAYS US WON'T SEND UKRAINE ROCKET SYSTEMS THAT CAN REACH RUSSIA

Dmitry Medvedev, the deputy head of Russia’s Security Council, said that was a "reasonable" decision.

He said that "otherwise, if our cities come under attack, the Russian armed forces would fulfill their threat and strike the centers where such criminal decisions are made."

Ukrainian firefighters extinguish fire

Ukrainian firefighters try to extinguish a fire in a warehouse after a Russian strike in Kharkiv, eastern Ukraine, Monday, May 30, 2022.  (AP Photo/Bernat Armangue)

Medvedev added that "some of them aren’t in Kyiv."

Russian pressure also continued in the south on Monday. Defense Ministry spokesman Maj. Gen. Igor Konashenkov said an artillery strike on a shipyard in the southern port of Mykolaiv destroyed Ukrainian armored vehicles parked there.

In the Kherson region, the Russia-installed deputy head of the regional administration, Kirill Stremousov, told Russia’s Tass state news agency that grain from last year’s harvest is being delivered to Russian buyers, adding that "obviously there is a lot of grain here." Ukraine has accused Russia of looting grain from territories its forces hold, and the U.S. has alleged Moscow is jeopardizing global food supplies by preventing Ukraine from exporting its harvest.

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Russia, meanwhile, has pressed the West to lift sanctions against it as it seeks to shift the blame for the growing food crisis — which has led to skyrocketing prices in Africa.

Zelenskyy urged France not to succumb to such "blackmail" as the Ukrainian president met Monday with French Foreign Minister Catherine Colonna.