"I never heard from President Trump that aid was conditioned on an announcement of (the investigations)," Sondland said.
US diplomat Gordon Sondland said Wednesday President Donald Trump never spoke to him about stalled military aid to Ukraine or any alleged link to Trump's demands for political investigations.
"I never heard from President Trump that aid was conditioned on an announcement of (the investigations)," Sondland told a congressional impeachment inquiry.
"I don't recall President Trump ever talking to me about any security assistance, ever," he added.
Democrats are investigating Trump for allegedly abusing his office by pressing a foreign power -- Ukraine -- to interfere on his behalf in the 2020 US election.
Trump asked his Ukrainian counterpart Volodymyr Zelensky for investigations into the US leader's political rivals while withholding military aid for the US ally, which is at war with Russian proxies in its east.
Sondland, the US ambassador to the European Union, told the House Intelligence Committee he had come to understand that there was a "quid pro quo" link between the mid-July suspension of $391 million in aid and Kiev announcing investigations into Trump's Democratic rival Joe Biden and the Democratic Party.
But he said Trump never spoke to him about the aid. He added that he had understood from Trump's personal lawyer Rudy Giuliani that a White House meeting Zelensky had sought with Trump had been conditioned on the investigations.
But the link between the frozen aid and investigations "was my own personal guess," Sondland told the committee.
Democrats have sought evidence that Trump personally set the quid pro quo on both a summit meeting and aid to support allegations that he tried to "bribe" Zelensky.
Sondland testified he had several direct phone calls with Trump this summer about Ukraine policy, but did not offer evidence of a direct command from the president.
Instead, he said, he worked at Trump's orders with Giuliani, who tied the White House meeting between the two leaders to Ukraine announcing the investigations.