"It is the saddest thing, I have to say, but I do not see the end to this war in sight," Kuleba told ABC News in a video interview from Kyiv.

There were also fears that Friday's meeting could result in the US and Russia imposing a peace deal on Ukraine against its will. Convincing Mr Trump to speak with Mr Zelensky in today's video-conference was seen as an important breakthrough, but Ukraine, the UK and other European nations remain frozen out of the key talks.

Small bands of Russian soldiers thrust deeper into eastern Ukraine on Tuesday ahead of a summit this week between Russian President Vladimir Putin and U.S. President Donald Trump, which European Union states fear could end in peace terms imposed on an unlawfully shrunken Ukraine.