Ukrainian forces are preparing for a "last battle" to control the southern port of Mariupol, besieged by Russians since the invasion, marines in the city said Monday.
"Today will probably be the last battle, as the ammunition is running out," the 36th marine brigade of the Ukrainian armed forces said on Facebook.
"It's death for some of us, and captivity for the rest," it added, saying it had been "pushed back" and "surrounded" by the Russian army.
It said it had been defending the port for 47 days and "did everything possible and impossible" to retain control of the city.
Russian forces have said that fighting has recently centred around the city's Azovstal iron and steel works and in the port.
The marines said that is where "the enemy gradually pushed us back" and "surrounded us with fire, and is now trying to destroy us."
The brigade said around half of its men are wounded.
"The mountain of wounded makes up almost half of the brigade. Those whose limbs are not torn off return to battle."
"The infantry was all killed and the shooting battles are now conducted by artillerymen, anti-aircraft gunners, radio operators, drivers and cooks. Even the orchestra."
The marines complained over a lack of support from Ukraine's military leadership: "No one wants to communicate with us anymore because we've been written off."
Mariupol has seen the most intense fighting since the Kremlin launched its attack on Ukraine, with the city being virtually razed to the ground.
Zelensky says he believes 'tens of thousands' killed in Mariupol
Ukrainian President Volodymyr Zelensky said Monday that he believed "tens of thousands" of people in Mariupol had been killed, as he asked South Korean lawmakers to provide military assistance.
Speaking to South Korea's National Assembly by video link, Zelensky said Russia had "completely destroyed" the besieged city of Mariupol.
"The Russians completely destroyed Mariupol and burned it to ashes. At least tens of thousands of Mariupol citizens must have been killed," he said, speaking by video link to South Korean lawmakers.
"But for Russia, Mariupol is just an example. Ladies and gentlemen, we've seen a lot of destruction like this in the 20th century."
Zelensky said South Korea could help his country's fight against Russia by providing military equipment from aeroplanes to tanks.
"If Ukraine receives such weapons, not only will they save the lives of ordinary people, but it will be a chance to save Ukraine," he said.
South Korea has given Ukraine some one billion won ($800,000 USD) of non-lethal military equipment, such as bulletproof helmets and medical kit, Seoul's defence ministry told AFP Monday.
But it turned down a recent Ukrainian request for anti-aircraft weaponry, saying that providing such weapons on the scale requested would impact South Korea's own "military readiness posture".
As a result of their own security situation, Seoul's ability to provide "lethal weapons systems to Ukraine is restricted," a defence ministry official told AFP.