Senate Majority Leader Mitch McConnell (R-Ky.) said he was not provided an explanation for why the Trump administration held up aid to Ukraine when he pressed senior officials on the matter over the summer.

"I was not given an explanation," McConnell told reporters Tuesday as the congressional furor grew over President Trump's interactions with Ukrainian President Volodymyr Zelensky.

McConnell said he spoke to Secretary of Defense Mark Esper and Secretary of State Mike Pompeo twice about the matter without receiving clarification for the delay in $391 million in aid to Ukraine.

"I was very actively involved in advocating [for] the aid. I talked to the secretary of Defense, the secretary of State once," he said.

"The good news was it finally happened," he added, noting the administration finally released the aid. "I have no idea what precipitated the delay."

Media outlets reported Tuesday that Trump asked his acting chief of staff Mick Mulvaney in July to put a hold on the aid before a phone call with Zelensky in which Trump suggested Ukraine conduct an investigation of Democratic presidential candidate and former Vice President Joe Biden or Biden's son, Hunter Biden.

House Democrats are considering voting on articles of impeachment in response to the reports, which were spurred by an intelligence community whistleblower.

McConnell said the matter should be handled by the Senate Intelligence Committee and noted that acting Director of National Intelligence Joseph Maguire is scheduled to appear before the panel Thursday.