Speaking from the frontlines in the eastern town of Avdiivka, a region at the centre of the fighting, soldiers described the difficulty of pushing back Russian forces at this stage.
One soldier, nicknamed 'Seagull' to protect his identity, said of the Russian attacks: "They are just razing everything to the ground.
"I have never seen anything like this."
Speaking to the New York Times, medic Oleksandr added: "We understand that it will be longer, harder and there will be more losses...(but) we will stay here as long as necessary."
A third soldier, nicknamed Synoptic, has been defending Avdiivka since the very start of the war in February 2022.
"It is necessary for us to have an advantage in everything — then a breakthrough is possible.
"We do not have this advantage. They have more aviation, radio reconnaissance, electronic warfare and more people. But even in such conditions, Ukraine is doing offensive operations in certain areas."
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On Monday, US defence secretary Lloyd Austin pledged further American support for Ukraine during a visit to Kyiv.
He announced "another $100 million drawdown... to provide additional artillery munitions, additional interceptors for air defence, and a number of anti-tank weapons" during a press conference at St Michael's Square in Kyiv.
The US State Department said the assistance includes three million rounds of small-arms ammunition and equipment for HIMARS precision rocket launchers.
Zelensky thanked the US for its support, saying that "there will be more artillery shells that are needed right now."