"Was there a 'quid pro quo?'" Sondland asked.
"It was the conditioning of official acts for something of great value to the president". And Sondland assumed Rudy was following Trump's orders.
Back on Capitol Hill, Sondland confirmed that the two are not tight. Burisma is the Ukrainian gas company where Biden's son Hunter served on the board.
He said it was his understanding that the president was holding up almost 400 million USA dollars (£361 million) in military aid in exchange for an announcement of investigations into the company that hired Mr Trump's political rival Joe Biden's son and Ukraine's alleged meddling in the 2016 election.
"And it was a very short, abrupt conversation", the ambassador said, which Trump had cited. "With regard to the requested White House call and White House meeting, the answer is yes". Sondland said he did not know until September that what was actually desired was an investigation into the Bidens.
In often stunning testimony, he painted a picture of a Ukraine pressure campaign that was prompted by Trump himself, orchestrated by Giuliani and well known to other senior officials, including Secretary of State Mike Pompeo.
In fact, the White House-produced memo of Trump's call with Zelensky which Trump frequently insists everyone read show that Trump asks Zelensky to do him a "favor" and speak to his attorney general about investigating the Bidens.
Sondland's testimony probably accelerates the moves by House Democrats to impeach the president and send the issue to the Senate for adjudication, though at this point the odds of conviction remain long, absent a significant shift in public opinion away from the president. "Tell Zelensky to do the right thing.' Something to that effect".
Sondland has said he told Andriy Yermak that the "resumption of USA aid would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks".
During Wednesday's questioning, Sondland said he doesn't think he would have said something like that, though he couldn't recall anything specifically refuting Holmes' claims. He also said he did not disagree with the accounts of the calls given by other witnesses.
Bill Taylor, the top United States diplomat in Ukraine, testified that Mr Trump asked Mr Sondland on that phone call if Ukraine would investigate alleged corrupt acts involving the Bidens and a conspiracy theory relating to the 2016 election.
"Ambassador Sondland has eviscerated the Trump/Republican narrative".
"I don't know him very well".
Sondland stressed last month that he had not discussed Ukraine with Mick Mulvaney, and had had minimal interactions with him.
Wednesday's testimony was the third time he has offered evidence in the impeachment inquiry - once behind closed doors, then in a written statement in which he revised some of his original statements.