However,Republicans who participated in the interview of Volker,said the evidence he presented fell far short of a"quid pro quo"- exchanging or withholding US assistance according to whether Ukraine helped damage a Trump political rival.
In a text from September 9,after news that the Trump administration had been withholding military assistance for Kiev,William Taylor,the US charge d'affaires in the Ukrainian capital,discussed the importance of the message Washington was sending to Kiev.
"With the hold (the delay in delivering the military aid),we have already shaken their faith in us,"Taylor said in a text message to Gordon Sondland,the US ambassador to the European Union.
"I think it's crazy to withhold security assistance for help with a political campaign,"Taylor said in another text.
Sondland responded that he believed Taylor was wrong about Trump's intentions,saying Trump had wanted to withhold the aid over concerns about corruption in Ukraine. In a text,he denied that there was a"quid pro quo,"linking assistance to Ukraine to whether Zelenskiy agreed to investigate the Bidens.
Trump froze nearly $400 million in US military assistance to Ukraine shortly before speaking to Zelenskiy,prompting accusations from Democrats that he had misused US foreign policy for personal gain.
House Intelligence Committee chairman,Democrat Adam Schiff.Credit:AP
Trump has denied wrongdoing and defended the call as"perfect,"and many of his fellow Republicans have blasted the impeachment investigation as blatant partisan politics.
Taylor has been the top US diplomat in Kiev since the Trump administration ordered the then-ambassador,Marie Yovanovitch,to return to Washington before the end of her term. Yovanovitch had been attacked in right-leaning media.
She is due to testify in the House inquiry next week.
The texts address a wide range of issues,including diplomats discussing Ukrainian officials'desire that their country be taken seriously by Washington,and not just used as a tool in domestic U.S. politics.
The three chairmen - Adam Schiff,who leads House Intelligence;Eliot Engel,who leads House Foreign Affairs and Elijah Cummings,who leads House Oversight - said they had far more material and hoped to make more of it public.
Reuters