U.S. Ambassador to the European Union Gordon Sondland told House impeachment investigators this week that he now remembers telling a top aide to Ukrainian President Volodymyr Zelenskiy that Ukraine would not receive U.S. military assistance until it committed to investigating the 2016 election and former Vice President Joe Biden, according to a person with knowledge of Sondland's testimony.

Sondland's latest testimony represents an update to depositions he gave in October to the three House committees leading the impeachment inquiry into President Donald Trump. The new testimony was in a four-page declaration to the committees.

According to that sworn declaration, Sondland told Congress this week that his memory has been refreshed after reviewing the opening statements from Bill Taylor, the acting ambassador to Ukraine, and Tim Morrison, a former adviser to Trump on Russian and European affairs.

Sondland said that by the beginning of September, he “presumed that the aid suspension had become linked to the proposed anti-corruption statement.”

Sondland said he also now remembered a Sept. 1 conversation with Andriy Yermak, a top Zelenskiy adviser, in Warsaw in which he told Yermak that “the resumption of U.S. aid would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks.”

He also said that soon after that he “came to understand” the statement would have to come from Zelenskiy himself. He claims he doesn’t remember how he learned that but it may have come from Trump's personal lawyer Rudy Giuliani or Kurt Volker, then-U.S. special envoy to Ukraine who resigned after his name appeared in a whistleblower complaint about Trump’s dealings with Ukraine.