Ukraine, which is hoping that the arrival of more Western weaponry will help it balance its own military forces against those of Russia and allow it to mount counterattacks to take back territory now under Russian control, on Sunday reiterated its refusal to make any concessions to Moscow.

"To bargain with a country that has taken hostages? Well, we have a better idea. The world has to agree on the transfer of MLRS (self-propelled multiple rocketlauncher) systems to Ukraine and other necessary heavy weapons to unblock the Black Sea. Then we will do everything ourselves," Mikhailo Podolyak, an adviser to Ukrainian President Volodymyr Zelenskyy, wrote on Twitter.

The official, a member of the Ukrainian delegation that participated in the talks with Russia during the first weeks of the conflict, talks which are currently paralyzed, made his remarks in response to suggestions in the US press that Kyiv may negotiate with Moscow to unblock its ports along its Black Sea coast.