Russian forces are now in control of most of Severodonetsk, the epicenter of the bloody battle for Ukraine's eastern Donbas region.
Street fighting continued to rage on Saturday in the eastern city, where Russian soldiers and Ukrainian troops are still locked in battle.
"The situation remains difficult. Fighting continues, but unfortunately, most of the city is under Russian control. Some positional battles are taking place in the streets," said Serhiy Haidai, the governor of Luhansk region, which makes up Donbas along with the neighboring Donetsk region.
The most active areas of fighting were Severodonetsk, Popasna, and the area of the Siverskyi Donets river, Haidai said on national television Saturday, adding Russian forces were using "highly destructive thermobaric rocket artillery."
A thermobaric weapon, also called an aerosol bomb, a vacuum bomb or a fuel air explosive (FAE), is a type of explosive that uses oxygen from the surrounding air to generate a high-temperature explosion. The fuel–air explosive is one of the best-known types of thermobaric weapons.
Thermobaric weapons are almost 100% fuel and as a result are significantly more energetic and last longer than conventional explosives of equal weight.
"Unfortunately, enemy artillery is simply dismantling floor-to-floor buildings that are used as shelters. In this sense, it is difficult because the enemy will be knocked out of one street, and then they will start dismantling neighborhoods house by house with tanks, artillery and grads," forcing Ukrainian forces in Severodonetsk to continuously move to new positions and regroup, the governor said.
The city of Severodonetsk is at risk of being cut off if the last bridge to the city is destroyed, according to the regional governor.
Ukraine's President Volodymyr Zelensky says Ukrainian troops are fighting for "literally every metre" of the city - which is still the focal point of the fighting in the eastern Donbas region.
Ukrainian forces have been pushed out of the city centre due to Russia having a significant advantage in artillery, Ukraine's military says.
Hundreds of civilians are sheltering in the city's Azot chemical plant, which is under heavy fire by Russian forces, the regional governor says.
If Russia prevails in the battle of Donbas, it will mean that Ukraine loses not only land but perhaps the bulk of its most capable military forces, opening the way for Moscow to grab more territory and dictate its terms to Kyiv. A Russian failure could lay the grounds for a Ukrainian counteroffensive — and possibly lead to political upheaval for the Kremlin.
Following botched early attempts in the invasion to capture Kyiv and the second-largest city of Kharkiv without proper planning and coordination, Russia turned its attention to the Donbas, a region of mines and factories where Moscow-backed separatists have been fighting Ukrainian forces since 2014.
Learning from its earlier missteps, Russia is treading more carefully there, relying on longer-range bombardments to soften Ukrainian defenses.
It seems to be working: The better-equipped Russian forces have made gains in both the Luhansk and Donetsk regions that make up the Donbas, controlling over 95% of the former and about half of the latter.
Ukraine pleads for more Western aid
Meanwhile, Ukraine is calling for more weapons to be sent from the West.
The calls come as Russia's defence ministry says its missiles have destroyed a large quantity of weapons and equipment in Donbas, including some sent by the US and European nations.
Defence ministers from around the world are meeting on Wednesday to discuss the situation in Ukraine, with weapons high on the agenda, says a Ukrainian presidential aide.
On 10 June, the Ukrainian Deputy Head of Military Intelligence, Vadym Skibitsky, said that Ukraine was almost out of ammunition. He added that Ukraine had nearly exhausted its supplies of artillery ammunition, and was reliant on the West to supply them.
Further, he said that Europe's supply of ammunition was also limited, needing to be restocked. According to Skibitsky, Russia had an advantage of 10 to 15 times more artillery systems than Ukraine. He said that Ukrainian forces were using 5,000-6,000 rounds a day, specifically 155 mm West-supplied rounds. Skibitsky claimed that Western rocket systems were needed to destroy Russian artillery.
According to a Ukrainian Presidential Aide, Ukraine was losing 100-200 soldiers per day.
Crisis and famine
The war has caused a spike in the global prices of energy -- Russia is a major producer of oil and gas -- and basic food stuffs. Before the war, Russia and Ukraine produced 30 percent of the global wheat supply, but grain is stuck in Ukraine's ports and Western sanctions have disrupted exports from Russia.
Addressing the Shangri-La Dialogue security summit in Singapore on Saturday, Zelensky warned of an acute food crisis, adding that the "shortage of foodstuffs will inexorably lead to political chaos".
Also Saturday, Gaiday cited reports of Russians loading trucks with Ukrainian wheat and taking it to Russian-controlled areas.
At the summit, Zelensky urged international pressure to end the blockade, speaking to delegates including Chinese Defence Minister Wei Fenghe, who on Sunday reiterated Beijing's position on the crisis.
"On the Ukrainian crisis, China has never provided any material support to Russia," he said, adding that it supported peace negotiations and hoped "NATO will have talks with Russia".
(with inputs from agencies)