– Two of President Donald Trump's top envoys to Ukraine drafted a statement for the country's new president in August that would have committed Ukraine to pursuing investigations sought by Trump into his political rivals, three people briefed on the effort said.

Their work on the statement is new evidence of how Trump's fixation with conspiracy theories linked to Ukraine began driving senior diplomats to bend American foreign policy to the president's political agenda in the weeks after the July 25 call between the two leaders.

The statement was worked on by Gordon Sondland, the U.S. ambassador to the European Union, and Kurt Volker, then the State Department's envoy to Ukraine, according to the three people who have been briefed on it.

The Ukrainians never released it. But if they had, Trump's aides would have effectively pressured a foreign government to give credence to allegations intended to undercut one of the Democratic Party's leading 2020 president candidates — former Vice President Joe Biden — without leaving Trump's fingerprints on it.

Volker spent Thursday on Capitol Hill being questioned by House investigators as Democrats pursued their impeachment inquiry into Trump's actions.

He disclosed a set of texts in September in which William Taylor Jr., the top American diplomat in Ukraine, alluded to Trump's decision earlier in the summer to freeze a military aid package to the country. He told Sondland and Volker: "I think it's crazy to withhold security assistance for help with a political campaign."

After speaking with Trump, Sondland texted back that there was no quid pro quo, adding, "I suggest we stop the back and forth by text."

The statement worked on in August by Sondland and Volker was among the topics that came up during the closed-door questioning of Volker on Capitol Hill.

The statement was written with the awareness of a top aide to the Ukrainian president, as well as Rudy Giuliani, Trump's personal lawyer and the de facto leader of a shadow campaign to push the Ukrainians to press ahead with investigations, according to one of the people briefed on it.

Volker also said that he warned Giuliani that Giuliani was receiving untrustworthy information from Ukrainian political figures about the Bidens, according to two people familiar with his testimony.

Volker said he tried to caution Guiliani that his sources, including Ukraine's former top prosecutor, were unreliable and that he should be careful about putting faith in the prosecutor's theories, said the people, who spoke on the condition of anonymity to discuss the closed-door meeting.

Democrats came away from the daylong deposition convinced that documents Volker provided to House investigators provide "ample evidence," Rep. Eric Swalwell, D-Calif., said, that the Trump administration planned to require Ukraine's president to investigate the Biden family's ties to the Ukrainian energy giant Burisma and look into the 2016 election to "exonerate Russia's role," if the foreign leader wanted to meet with the American president.

The Washington Post contributed to this report.