WASHINGTON (Reuters) - Francis Rooney, a Republican member of the U.S. House of Representatives who expressed concerns about President Donald Trump’s dealings with Ukraine, said on Saturday he would not run for a third term.

“I don’t really think I want one (third term)” Rooney, of Florida, told Fox News.

He said he was concerned about an acknowledgment by Mick Mulvaney, the White House acting chief of staff, on Thursday that the Trump administration had held up nearly $400 million in aid for Ukraine to pressure the country to investigate a debunked conspiracy theory about interference in the 2016 U.S. elections.

Trump and administration officials had denied for weeks that they had demanded a “quid pro quo” - a Latin phrase meaning a favor for a favor - for delivering the U.S. aid, a key part of a controversy that has triggered an impeachment inquiry in the House against the Republican president.

“The president was saying no quid pro quo, I was giving the guy the benefit of the doubt...and come to find out there was a clearer quid pro quo admitted to by his chief of staff,” Rooney told Fox.

Mulvaney’s comments, which the White House later tried to walk back, “are probably going to drive some people just to rethink this just a little more,” Rooney said.

He said he was also concerned with Trump’s removal of U.S. forces in Syria which has allowed Turkey to launch an offensive against Kurdish fighters who were a U.S. ally in the fight against Islamic State.

Rooney also said his decision was based on support for term limits and frustration with partisanship in Washington.

Rooney had tweeted on Friday that he had never endorsed the impeachment enquiry led by Democrats, but since it was underway, “I am in favor of finding out all of the factual information available in this process.”