Ukrainian President Volodymyr Zelensky said the situation in the eastern front-line city of Bakhmut was “increasingly difficult”.
Russian forces have been trying to capture the city for over six months.
“The enemy is constantly destroying everything that can be used to defend our positions,” Zelensky said.
The Ukrainian leader’s remarks came as US Treasury Secretary Janet Yellen warned China against Russia arming itself during a visit to Kiev on Monday.
Since Russia invaded Ukraine just over a year ago, the most bloody fighting has taken place in Bakhmut, in Ukraine’s Donetsk region, partly under the control of Russia and its separatist allies.
Recently, Russian forces have stepped up efforts to seize the industrial city, and their forces are growing in strength.
The self-proclaimed Donetsk People’s Republic’s separatist leader, Denis Pushirin, said that “virtually every road” to the city was “underneath.” [Russian] fire control”.
Speaking about the situation in his nightly speech, President Zelensky said his success in gaining a foothold in Bakhmut and securing its defenses had been severely compromised by the new Russian onslaught.
“I am grateful to each and every one of you who are heroically supporting the community,” he said.
President Zelensky also reiterated calls for the deployment of modern fighter jets so that “the entire territory of our country” can be protected from “Russian terrorism.”
Janet Yellen announced in a surprise visit to Kiev on Monday that she had sent the latest $1.25 billion (£1 billion) in economic and budget aid to Ukraine.
Yellen repeated a message from US President Joe Biden. His own visit to Kiev last week Washington will support Ukraine for as long as it takes to win the war.
speak to CNNYellen added that while the Russian economy has not yet collapsed under heavy sanctions against Russia by the West, she expects it to weaken over time.
She also said that Russia’s ability to replenish military equipment destroyed in the attack on Ukraine was “increasingly jeopardized” and that China’s move to supply Russia with such weapons ” It would have serious “consequences,” he added.
“It is very clear that no country will tolerate systematic violations of the sanctions we have introduced with the intention of depriving Russia of access to the military equipment to wage this war,” she said. rice field.
“And we have been very clear to the Chinese government and to Chinese companies and financial institutions that the consequences of violating these sanctions are very serious.”
The meeting between Chinese diplomat Wang Yi and Russian President Vladimir Putin in Moscow last week seemed to many to indicate the close relationship between China and Russia.