Ukrainian President Volodymyr Zelenskiy has dismissed suggestions US President Donald Trump froze aid to pressure him to launch a probe into Joe Biden.
Ukraine's leader said that in discussions with Trump, he repeatedly stressed the importance of US military aid to help Ukraine battle Russian-backed separatists.
The Pentagon announced plans in June to send $US250 million ($A373 million) in aid to Ukraine, but its delivery was delayed, before the phone call took place.