U.S. Ambassador to the European Union Gordon Sondland is expected to tell Congress this week that President Trump had told him by phone to write a text message denying there was a quid pro quo deal in regards to Ukraine, the Washington Post reported Saturday.

In a text exchange that went public, the top U.S. diplomat to Ukraine Bill Taylor told Sondland that he thinks it "is crazy to withhold security assistance for help with a political campaign."

Taylor was referring to the nearly $400 million in U.S. military aid to Ukraine that was held up in order to possibly pressure the Ukrainian government to investigate Hunter Biden's activities in the country.

"Bill, I believe you are incorrect about President Trump's intentions. The President has been crystal clear: no quid pro quo's [sic] of any kind. The President is trying to evaluate whether Ukraine is truly going to adopt the transparency measures and reforms that President Zelensky promised during his campaign," Sondland responded, with the content of that message possibly dictated to Sondland from Trump himself in a phone call.

Volodymyr Zelensky was elected as President of Ukraine in May, with Trump calling Zelensky on July 25.

Sondland, a wealthy donor that gave $1 million to Trump's inaugural committee, is expected to testify Thursday. He is also expected to say that he is not sure whether Trump's no quid pro quo statement was the truth.

The Trump administration has reportedly tried to block Sondland's testimony.

Sondland is also going to testify that he was working with Trump's personal lawyer Rudy Giuliani to get Ukraine to make a statement that it would investigate corruption. Federal prosecutors are reportedly investigating Giuliani's dealings with Ukraine.

Earlier this week, two of Giuliani's associates, Lev Parnas and Igor Fruman, were arrested on campaign finance violations. They had allegedly tried to funnel foreign money into domestic political candidates running for office in order to buy political influence.

Speaker of the House Nancy Pelosi announced an impeachment inquiry into President Trump on Sept. 26, after an anonymous whistleblower said that Trump had made a "promise" with an unnamed foreign leader, which was later revealed to be Zelensky. At least 228 Democrats in the House as of this week have said that they support an impeachment inquiry.