The view among the national security officials was unanimous: Military aid to Ukraine should not be stopped. But President Donald Trump's acting chief of staff thought otherwise.

As the aid was being blocked this summer, Ukraine officials began quietly asking the State Department about the holdup. The concern was clear for the young democracy battling an aggressive Russia.

"If this were public in Ukraine it would be seen as a reversal of our policy," said Catherine Croft, the special adviser for Ukraine at State, who fielded the inquiries from the Ukrainians.

"This would be a really big deal," she testified. "It would be a really big deal in Ukraine, and an expression of declining U.S. support for Ukraine."

Croft's remarks were among the transcripts released Monday from the House impeachment inquiry of President Donald Trump.

And they begin to chisel away at a key Republican defense of Trump. Allies of the president say Trump did nothing wrong because the Ukrainians never knew the aid was being delayed.

Eventually, the White House released its hold and the funds were sent to the ally.

The impeachment inquiry is looking at whether Trump violated his oath of office by holding back the congressionally approved funds while he asked the new Ukraine President Volodymyr Zelenskiy for a favor— to investigate political rival Joe Biden's family and the 2016 U.S. presidential election.

Transcripts of testimony from closed-door interviews with Croft and another Ukraine specialist at State, Christoper Anderson, as well as the Defense Department's Laura Cooper, come as House Democrats are pushing ahead to this week's live public hearings.

Cooper told investigators that, in a series of July meetings at the White House, she came to understand that Trump's acting chief of staff, Mick Mulvaney, was holding up the military aid for the U.S. ally.

"There was just this issue of the White House chief of staff has conveyed that the president has concerns about Ukraine," she said.

When she and others tried to get an explanation, they found none.

"We did not get clarification," she said.

"My sense is that all of the senior leaders of the U.S. national security departments and agencies were all unified in their — in their view that this assistance was essential," said Cooper, an assistant defense secretary. "And they were trying to find ways to engage the President on this."

Croft and Anderson testified about the oversized reach of Trump lawyer Rudy Giuliani into foreign policy on Ukraine in unsettling ways as he portrayed Zelenskiy's new government as an "enemy" of Trump.

Croft told investigators of her "trepidation" of taking on the role in spring of adviser to the special envoy to Ukraine, Kurt Volker, because she worried that Giuliani was influencing Trump to change U.S. policy toward the ally.

She said she theorized that by "painting sort of Ukraine as being against Trump" it could help the president "distract from a narrative" that Russia had interfered in the 2016 U.S. election to help him.

Anderson, who held the special adviser role before Croft, said, "I had the fear that if Giuliani's narrative took hold, that the Ukrainian Government was an enemy of the President, then it would be very hard to have high-level engagement."

He said Volker had warned him, "Giuliani is not moving on to other issues, and so this might still be a problem for us moving forward."

Cooper said she and other aides were asking questions about what legal authority the White House had to halt congressionally approved aid for Ukraine.

She said it was "unusual" to have the congressional funds suddenly halted that way. The Pentagon was "concerned."

Cooper told investigators that it was when Volker visited in August that he explained there was a "statement" that the Ukraine government could make to get the security money flowing.

It was the first she had heard of what is now the quid pro quo central to the impeachment inquiry — the administration's push for the Ukraine government to investigate Trump's political rivals as the funding was being withheld.

"Somehow an effort that he was engaged in to see if there was a statement that the government of Ukraine would make," she said, "that would somehow disavow any interference in U.S. elections and would commit to the prosecution of any individuals involved in election interference."

Cooper described the Ukraine Security Assistance Initiative, saying it involved a range of items such as night vision goggles, vehicles, sniper rifles and medical equipment.

"Security assistance is vital to helping the Ukrainians be able to defend themselves," Cooper said.

Because Ukraine and Georgia are two "front-line states" facing Russian aggression, the U.S. needed to "shore up these countries' abilities to defend themselves."

"It's in our interest to deter Russian aggression elsewhere around the world," she said.

Associated Press writers Alan Fram, Zeke Miller, Eric Tucker, Mike Balsamo, Matthew Daly and Laurie Kellman in Washington contributed to this report.