WASHINGTON – Two State Department officials with expertise on Ukraine are scheduled to appear Wednesday before lawmakers leading the impeachment inquiry of President Donald Trump.

Catherine Croft and Christopher Anderson, who both worked under previous key witness Kurt Volker, the former U.S. special envoy to Ukraine, are scheduled to appear Wednesday before the House Oversight, Intelligence and Foreign Affairs committees.

Croft's background includes work on Ukraine for both the State Department and the National Security Council. Similarly, Anderson's resume includes working at the U.S. Embassy in Kyiv, Ukraine's capital.

The opening statements of both Croft and Anderson were obtained by USA TODAY. Here are some of the key points from the prepared remarks"

Croft says a lobbyist told her Ukraine Ambassador Marie Yovanovitch should be fired, according to Croft's opening statement.

Croft was unaware of a hold on aid to Ukraine until a July 18 video conference with the Office of Management and Budget, where she was informed a hold was placed on security assistance to Ukraine, stemming from an order "at the direction of the President."

Anderson will say that former National Security Adviser John Bolton said Trump's personal attorney Rudy Giuliani, who took part in a pressure campaign in Ukraine, "could be an obstacle to increased White House engagement."

Read their opening statements in full below: