Ukraine's allies must step up support and provide proper air defenses, as Kyiv fends off Russian forces in several flashpoints, Ukrainian President Volodymyr Zelenskyy said.

In his nightly address on Sunday, Zelenskyy said the world must "finally hear" the pain inflicted on Kharkiv, Ukraine's second-largest city, which has been subject to a recent wave of attacks and bombings.

"It is quite obvious that our existing air defense capabilities in Ukraine are not sufficient and it is obvious to our partners," Zelenskyy said.

Earlier on Sunday, the president warned during a video meeting that Kyiv would lose the war if the US Congress doesn't approve a major military aid package, which has been pending for months amid Republican opposition.

"It is necessary to specifically tell Congress that if Congress does not help Ukraine, Ukraine will lose the war," Zelenskyy said during a video meeting.

It would be "difficult" for Ukraine to "stay," or survive, without the aid, Zelenskyy added. "If Ukraine loses the war, other states will be attacked."

zc/ab (AFP, Reuters, dpa, AP)