When U.S. envoy to Ukraine Bill Taylor testified to congressional Democrats' closed-door impeachment inquiry, he created huge headaches for the Trump administration by detailing their efforts to push Ukraine to probe former Vice President Joe Biden's son.

But Taylor also made some problems for Ukraine's president. And now, aides in President Volodymyr Zelensky's office are going on the record to push back. The episode shows just how complicated relations between the U.S. and Ukraine have become as the Trump impeachment inquiry unfolds, according to The Daily Beast.

In his testimony last month, Taylor – America's top diplomat in Kyiv – implied that two Zelensky aides blamed Ukraine, rather than Russia, for the long-running, bloody war in the eastern part of the country. Taylor's words weren't crystal-clear, but the comment set off a political firestorm in Ukraine, where Russian-backed separatist fighters have killed thousands of Ukrainians. Critics of the country's newly elected president, Volodymyr Zelensky, seized on Taylor's testimony as evidence that Zelensky's team is running interference for Russia.

The conversation Taylor described began when then-U.S. special envoy Kurt Volker urged the two Zelensky aides, Igor Novikov and Andriy Yermak, not to prosecute Petro Poroshenko, the country's last president and Zelensky's old rival. Poroshenko associates are linked to a huge military procurement scandal in Ukraine.

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Taylor told congressional investigators that after Volker urged the two Ukrainians to steer clear of charging Poroshenko, they had an emotional response.

"[T]hey responded, take a look at this," Taylor said. Then he said that Yermak and Novikov showed Taylor and Volker pictures on their cellphones "of their relatives – one was a brother, one was a cousin – who had been killed or wounded in the east."

"[T]hey said, Poroshenko is responsible for this," Taylor told investigators.

Taylor's description of that comment has drawn little attention in American media (Novikov commented briefly on it to The Daily Beast last week). But it set off a significant controversy in Kyiv. Poroshenko allies seized on the testimony to say the Zelensky team was blaming the former president, Poroshenko, for the war in the east–and, in doing so, protecting Russia from accountability for the violent conflict.

"[Th]is testimony... puts the blame for the war against Ukraine on Ukraine, not on Russia," said Iryna Herashchenko, one of Poroshenko's allies in Ukraine's parliament.

And now, Yermak is pushing back.

"I have never said that Poroshenko is responsible for the start of the war in Donbas," he told The Daily Beast in a statement. "What I said was, 'No one is above the law."