WASHINGTON — Two career diplomats will testify before House impeachment investigators Wednesday that President Donald Trump displayed a deeply pessimistic view of Ukraine that was out of step with officials at the White House and State Department who saw support for the European country as critical in its battle with Russian-backed separatists, according to their prepared remarks obtained by The Washington Post.

The State Department officials, Catherine Croft and Christopher Anderson, will say their optimistic view of Ukrainian President Volodymyr Zelensky clashed with a darker outlook of the new government held by Trump and an informal channel of actors linked to the president's attorney Rudy Giuliani.

Anderson, a career Foreign Service officer, will detail efforts when U.S. officials tried to demonstrate support for Ukraine only to be batted down by the White House, including after Russian forces attacked and seized Ukrainian military vessels in the Sea of Azov in 2018.

"While my colleagues at the State Department quickly prepared a statement condemning Russia for its escalation, senior officials in the White House blocked it from being issued," Anderson was set to testify.

Croft, who worked on Ukraine issues at the White House and the State Department, will say that "throughout" her time in the Trump administration she heard the president "describe Ukraine as a corrupt country," both "directly and indirectly."

The prepared testimony does not add significantly to the specific claims by other U.S. officials alleging that Trump tried to pressure Ukraine into investigating his political rivals by withholding about $400 million in military aid and diplomatic support to Ukraine.

Croft and Anderson did not enjoy as much visibility into senior-level decision-making as some of their peers, such as former deputy national security adviser Charles Kupperman, whom House Democrats have struggled to bring in to testify. But they do offer new insight into how a shadow foreign policy executed by people outside of government undermined the work of U.S. officials.

Specifically, Croft mentions receiving inexplicable phone calls from Washington lobbyist Robert Livingston, "who told me that Ambassador Yovanovitch should be fired," referring to Marie Yovanovitch, then the top U.S. envoy in Kyiv.

"He characterized Ambassador Yovanovitch as an 'Obama holdover' and associated with George Soros," she plans to testify.

Yovanovitch was recalled from her position earlier this year after Giuliani and his associates waged a campaign of unsubstantiated allegations about her being opposed to Trump and supportive of Joe Biden, the former vice president now seeking the Democratic nomination for president in 2020. Yovanovitch denied those allegations in her sworn testimony earlier this month.

“It was not clear to me at the time — or now — at whose direction or at whose expense Mr. Livingston was seeking the removal of Ambassador Yovanovitch,” she will say.

Livingston, a former Republican congressman from Louisiana, was chosen as the successor to Newt Gingrich as speaker of the House in 1999, but he declined the position after revelations of an extramarital affair. After leaving Congress, he formed the Livingston Group, one of Washington's most influential lobbying firms. His firm has represented clients in the Middle East and around the world, including political figures in Ukraine such as former prime minister Yulia Tymoshenko, according to Justice Department documents.

Croft is expected to say she notified her boss, Fiona Hill, and another State Department official, George Kent, of Livingston's activities, and declare that she is "not aware of any action that was taken in response."

The testimony was scheduled for a pivotal moment in the impeachment inquiry, as Democrats prepare to move the effort into the open with public hearings.

The House is expected to vote this week on a Democratic resolution laying out rules for those hearings in the Intelligence Committee and formally authorizing House Republicans to request testimony and documents, subject to votes by the Democratic-majority panel.

Unveiled Tuesday afternoon, the resolution was expected to receive a vote Thursday, according to multiple Democratic aides who were not authorized to speak publicly.

The move responds in part to Republican attempts to undermine the impeachment inquiry by painting it as a secretive effort to oust Trump from office.

White House press secretary Stephanie Grisham slammed the resolution Tuesday night in a statement, saying it "confirms that House Democrats' impeachment has been an illegitimate sham from the start."

In the past month, investigators have heard testimony or received briefings from about a dozen officials, and they have subpoenaed or requested documents from about 18 others. The inquiry formally began Sept. 24.

Two additional witnesses are scheduled to testify before the end of the week: Timothy Morrison, special assistant to the president and senior director for Europe and Russia on the National Security Council, on Thursday, and Robert Blair, senior adviser to acting Trump chief of staff Mick Mulvaney, on Friday.

The Washington Post’s Tom Hamburger contributed to this report.