STORY: President Volodymyr Zelenskiy insisted on Saturday that Ukraine would prevail in its almost four-month-long war with Russia.
Speaking remotely at the Shangri-La Dialogue in Singapore, Zelenskiy said it is "on the battlefields in Ukraine that the future rules of this world are being decided."
Ukraine has appealed for a swifter delivery of heavy weapons from the West
saying Russian forces have ten times more artillery pieces than Ukrainian forces.
The conflict has become focused on a grinding artillery slugging match over Sievierodonetsk.
The eastern city is one of the last Ukrainian-controlled parts of Luhansk province which Russia wants to seize, along with its twin city Lysychansk.
Ukraine's Luhansk Governor said Russian forces control most of Sievierodonetsk but that Ukraine still controls the Azot chemical plant where hundreds of civilians are sheltering.
The battle over Sievierodonetsk and its destruction recall weeks of bombardment of Mariupol.
The southern port city's mayor has said Mariupol's sanitation systems are broken and corpses are rotting in the streets.
Vadym Boichenko told national television that there was an outbreak of dysentery and cholera.
He called on the United Nations and the International Committee of the Red Cross to work on establishing a humanitarian corridor to allow remaining residents to leave the city, which is now under Russian control.