Kent also told congressional investigators that Giuliani conducted a "campaign full of lies and incorrect information" against Marie Yovanovitch before she was recalled from her post as ambassador to Ukraine, according to the transcript of his testimony.
In a letter sent on Wednesday to Devin Nunes, the top Republican on the House Intelligence Committee and a strong Trump supporter, the whistleblower's lawyers reiterated that their client was willing to answer written questions.
Kent, along with William Taylor - the top USA diplomat in Ukraine - will testify publicly on November 13.
Sources familiar with the investigation said Kent's transcript would be made public on Thursday.
Jennifer Williams, a career foreign service officer and special adviser to Pence for Europe and Russian Federation, arrived at the U.S. Capitol to testify behind closed doors on Thursday morning with members of the House of Representatives Foreign Affairs, Intelligence and Oversight committees.
A new report says that if former White House National Security Adviser John Bolton can get clearance from a federal court, he'll be prepared to defy the Donald Trump administration's orders and testify before the Ukraine impeachment inquiry. Bolton's attorney said he would not appear voluntarily and he has not yet been subpoenaed. The complaint accused President Trump of using USA military aid to Ukraine to secure an investigation by the Ukrainian government into former Vice President Joe Biden and his son for political gain.
Even as Bolton was a no-show, an aide to Vice President Mike Pence came to the Capitol to speak with impeachment investigators.
The battle is likely to go to the Supreme Court and could spill into next year.
Trump has denied any quid pro quo, but Democrats say there is a singular narrative developing since the president's July 25 call with Ukrainian President Volodymyr Zelenskiy when he first asked for 'a favor'. Cooper had previously said Bolton wouldn't appear without one.
Williams was one of a handful of USA officials who listened in on the call.
They are trying to determine whether Trump froze $391 million in US security assistance for Ukraine to put pressure on Zelenskiy to conduct the investigation, misusing USA foreign policy for his personal gain.
Senate Republicans have so far shown little appetite for ousting the president.
Sondland, in an addendum to his sworn earlier testimony, said that military assistance to the East European ally was being withheld until Ukraine's new president agreed to release a statement about fighting corruption as Trump wanted. Sondland's revised testimony prompted many Democrats to interpret that as evidence of a quid pro quo.
Democrats have countered that any quid pro quos are usually in furtherance of USA interests overseas, not the personal interests of a president looking to damage a potential 2020 election rival.
The report and Trump's denial comes as Democrats prepare to move the impeachment inquiry into the public hearing phase.
"Those open hearings will be an opportunity for the American people to evaluate the witnesses for themselves, to make their own determinations about the credibility of the witnesses, but also to learn firsthand about the facts of the president's misconduct", the intelligence committee's Democratic chairman, Adam Schiff, said on Wednesday.
Williams is among the last witnesses scheduled to provide a closed-door deposition before public hearings begin next week.