Clare County Council says it has no record of any communications by Mr Varadkar on the issue.
"We face enormous challenges from Brexit, which has undoubtedly changed the political climate in Northern Ireland", Varadkar said in the text of a speech due to be delivered at an event in Washington celebrating 20 years of peach in Northern Ireland.
In the call, Mr Varadkar said that the future President told him he had a problem near the golf course, where a wind farm was being proposed.
Friends of the Irish Environment say that they had objected to the development on ecological grounds, but declined Trump's offer of help to maintain their independence.
The warning came from the Department of Local Government on March 9th last, and was sent to all Councillors nationwide, including in Clare.
A spokesman for Mr Varadkar later moved to clarify the taoiseach's remarks, insisting there was nothing inappropriate about what he had done.
The company behind the proposed windmill also raised their concerns about Leo's confession.
Clare Coastal Wind Power, the company that sought planning permission, said in a statement that it is "disappointed" by the Taoiseach's actions and that it is reviewing the situation.
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The three then walked into the East Room where Prime Minister Varadkar presented Trump with a bowl of Shamrocks ahead of St. Patrick's Day.
Taoiseach needs to be more transparent in relation to his intervention with Clare County Council on behalf of President Trump regarding a planning application for a wind farm.
"There is more to this than meets the eye and the Taoiseach needs to clarify exactly how and when he made the representations and whether or not it was appropriate".
The Taoiseach also did not respond when he was asked if he would raise marriage equality with the Vice President.
Three or four years ago he received a call from businessman Mr Trump and contacted the planning authorities.
Opposition parties and environmental groups have accused the Taoiseach of dropping a "diplomatic clanger" over his backing of Donald Trump's opposition to a wind farm proposal near his Doonbeg resort.
Mr Harris said the suggestion that the incident amounted to an "intervention" in the planning process by Mr Varadkar was to misuse the word. "It was not a court case or judicial matter".