When Ukrainian officials found out U.S. military aid was being withheld by the White House has become a key question in the impeachment case against President Trump and whether there was a quid pro quo.

Fresh testimony in public hearings Wednesday appeared to suggest the Ukrainians had learned of the hold much earlier than previously known, after a senior Pentagon official, Laura Cooper, said the country's embassy had been asking one of her staffers about it as early as July 25. That is the same day that Trump pressed Ukraine’s president Volodymyr Zelenskiy during a phone call to investigate his Democrat rival, Joe Biden.

But in Kyiv, Ukrainian officials have painted a muddled timeline of when precisely Zelenskiy’s administration discovered the $400 million in aid was being held up. Zelenskiy’s former top national security adviser insisted to ABC News on Thursday he and the administration had been in the dark for most of the summer, despite Cooper’s testimony and statements from Ukraine’s then-ambassador to the U.S. seeming to support it.

Ukrainian officials have previously said they only discovered the aid was frozen when it was made public by a Politico article on Aug. 28, more than a month after a hold was placed on the assistance. The president’s Republican defenders have argued that is proof that Trump cannot have sought to use the assistance as leverage, since Zelenskiy didn’t know it was being withheld.

But on Wednesday, Cooper, the deputy assistant secretary of defense for Russia, Ukraine and Eurasia, testified that a member of her staff had received a call on July 25 from a contact at Ukraine’s embassy asking “what was going on with the Ukraine assistance.” Cooper said her staff received two more messages that day from the State Department saying the Ukrainian embassy and “the Hill” knew there was a "situation" around the aid.

Ukraine has not confirmed that outreach, but an October interview given by Ukraine’s then-ambassador to Washington now appears to potentially support that sequence of events.

In the interview given to the Ukrainian news site LB.ua, the now former ambassador, Valeriy Chaliy, said he had inadvertently discovered the aid was stalled in the summer before it became public, after he learned some private companies with contracts tied to it were facing delaying in payments.

“I contacted representatives of Congress, the Senate, so that they would pay attention to this question, so that the aid would arrive on time,” Chaliy said in the interview published Oct. 14. He said he was worried the delay might mean Ukraine would not receive the aid before the U.S. fiscal year expired on Sept. 30 and therefore be lost.

Chaliy in the interview said he informed his superiors in Kyiv of the issue when he discovered it but never received any response. He said he then decided to make the inquiries on his own initiative.

The comments from Chaliy appear to support the idea that Ukraine’s government knew early on that there was at least an issue with the aid.

But on Thursday, Zelenskiy’s former top national security adviser, Oleksander Danyliuk, insisted that despite the alleged contacts with the embassy, neither he nor-- as far as he was aware— the Ukraine president’s senior administration had any idea the assistance was delayed until it was made public on Aug. 28.

Danyliuk -- who headed Zelenskiy’s national security council throughout the summer and was present for the July 25 call with Trump -- said he learned of the hold through the Politico article. If the embassy had known, the message somehow had not made it back to Kyiv, he said.

“I didn’t know and I don’t think anyone else knew. And I should have,” said Danyliuk. “For us, that was a complete surprise.”

A former finance minister with a reputation as a reformer, Danyliuk was responsible for helping manage U.S. assistance until he stepped down in late September. He said he had never received any message from Chaliy about the aid. If the embassy had known, Danyliuk said he was baffled why he wouldn’t have been told or if other officials were, why they would not have reacted.

He noted that even if the embassy had discovered contractors were going unpaid, it would not have led them to immediately assume there was a total hold on the aid or that it had come from the White House.

Danyliuk was outside the channel led by Gordon Sondland, the U.S. ambassador to the European Union, and Trump’s envoy to Ukraine Kurt Volker, who were pushing the Ukrainians to promise the investigations, they said acting on directions from Trump’s personal lawyer Rudy Giuliani. Those discussions were handled by Zelenskiy’s close aide and friend, Andriy Yermak, who met with Giuliani. Danilyuk was present at a meeting in the White House on July 10, though, where Sondland raised the investigations and he later told U.S. ambassador William Taylor he was concerned about Zelenskiy being used as a pawn in American domestic politics.

If the embassy’s message did fail to reach Kyiv, one possible explanation might be it was sent during a period of confusion during Zelenskiy’s transition into office when he was without his own cabinet and when his team were publicly feuding with Chaliy. Zelenskiy’s administration considered Chaliy too close to his predecessor, Petro Poroshenko, and worried he was disliked by the Trump administration, which believed he had taken part in an attempt to smear President Trump.

The message also appears to have gotten lost on the U.S. side. Cooper testified that Ukraine’s embassy’s inquiries did not reach her at the time and she only learned of them this month from her staff, who told her after listening to her first closed-door testimony from October.

It was unclear if the Ukrainians ever got responses that the aid was being held up. Cooper said her staffer told the Ukrainian embassy contact that everything was OK, but to check with the State Department. She said her staff recalled having other meetings with the embassy in August, where the aid came up but didn’t remember when exactly.

Prior to Cooper, the order of events described by other testimony appeared to support the idea that much of Zelenskiy’s administration was ignorant of the hold for most of the summer. Taylor, testified that as far as he was aware, the Ukrainians only discovered it when it became public on Aug. 29 and began urgently contacting him.

Former White House national security adviser John Bolton was in Kyiv on an official visit on Aug. 27, one day before the hold became public, but the Ukrainians, including Danyliuk, never raised the issue, according to Taylor’s testimony.

“Amazingly, news of the hold on security assistance did not leak out until August 29th. I, on the other hand, was all too aware of and still troubled by the hold,” Taylor said in his testimony.

Once it became public, Ukrainian officials have described urgently trying to contact their counterparts. Danyliuk said he tried to reach Bolton. Zelenskiy then brought up the issue of the aid days later with Vice President Mike Pence at a meeting in Warsaw on September 1. Ten days later, the hold was lifted, following bi-partisan calls on Trump to do so and amid intensifying scrutiny following the submission of the Whistle-blower complaint that triggered the impeachment inquiry.

Another Ukrainian official in October told ABC News that after they had realized the aid was being held it had not taken them long to understand that the decision must have come from Trump.

“From almost all our others U.S. counterparts, the Pentagon, Congress, we got the message, that ‘Guys we have nothing against this. It’s not us’,” the official said. “And then the final answer was very short and clear, it was clearly the decision of Person Number One,” said the official, who requested anonymity because of the sensitivity of the subject.

The official said they had learned of the hold in late August from another official involved in bilateral relations but did not say when precisely.

Regardless of when they knew, however, once it became public Zelenskiy’s team was quickly informed by Gordon Sondland the freeze on the aid was linked to the investigations.

Sondland in his testimony on Wednesday said again that he had told the top Zelenskiy aide, Yermak, about the link on the side-lines of the Warsaw meeting. Sondland said he told Yermak there for the first time the aid was unlikely to be released without a public statement from Zelenskiy promising the investigations.

Danyliuk insisted that even after that meeting, he didn't realize the aid was tied to the investigations and that he believed the hold was the result of a “technical” issue. He said, Yermak had never told him of Sondland’s conversation, saying he only learned it while reading the Congressional testimonies.

Zelenskiy’s administration though had for months understood there was another part of the quid pro quo--that a White House visit was contingent on the investigations, sources close to the administration said. Sondland and Volker testified they had made clear to the Ukrainians that a public statement was needed for a meeting with Trump and text messages released by the Congressional committees show Yermak agreeing to have Zelenskiy make a statement if a date for a visit was given.

A number of Zelenskiy advisers were strongly opposed to the Ukrainian president making such a statement, believing it was inappropriate for a head of state and could damage the strong bi-partisan report for Ukraine in Congress. Some officials also said they viewed it as unnecessary, believing Congressional pressure would likely force the release of the aid anyway. But after Sondland’s message, Zelenskiy arranged to make the announcement in a CNN interview in early September, only to cancel it after the aid was unfrozen on Sept. 11, according to Taylor’s testimony.

Sondland testified given what had happened over the visit, he had concluded there was no chance the aid would be released either without a statement.

If you can’t get a meeting without a statement, “what makes you think you’re going to get a $400 million check?” he told Wednesday’s hearing.