Acting U.S. ambassador to Ukraine Bill Taylor arrives on Capitol Hill before a closed-door hearing with members of Congress in Washington, October 22, 2019.

A top U.S. diplomat shared broad concerns with the Trump administration's policy toward Ukraine with lawmakers, and testified he was told military aid to the country was dependent on its government committing to investigations the president wanted, according to a transcript of his House deposition released Wednesday.

Bill Taylor, the U.S. charge d'affaires in Ukraine, spoke to lawmakers last month in a closed-door session as part of the House's impeachment inquiry. House Democrats released his testimony a week before he was slated to appear at the investigation's first public hearing on Nov. 13.

In his opening statement to lawmakers, Taylor said another diplomat told him the president withheld military aid as he waited for public assurances that Ukraine would launch investigations he wanted into the Biden family and allegations of Ukrainian interference in the 2016 election.

″'Everything' was dependent on such an announcement, including security assistance," U.S. Ambassador to the European Union Gordon Sondland said to Taylor in September, according to Taylor's opening statement. "He said that President Trump wanted [Ukrainian President Volodymyr] Zelensky in a box by making [a] public statement about ordering such investigations."

The House has looked into whether Trump abused his power and compromised national security by urging Ukraine to probe former Vice President Joe Biden, one of the president's chief rivals for the White House in 2020, and Biden's son Hunter. Lawmakers have also tried to determine whether Trump withheld about $400 million in military aid in exchange for the probes from Ukraine.