President Trump’s preferred ambassador to Singapore has withdrawn her nomination, following a protracted delay in the Senate.

“I have come to this decision, because I believe in your mission,” K.T. McFarland, Trump’s former deputy national security adviser, wrote in a Friday letter to the president. “Know that I have no intention of withdrawing from the national debate and I want to help you in whatever way I can.”

McFarland joined Trump’s team at the recommendation of former Secretary of State Henry Kissinger. Still, her career in the administration became embroiled in the controversy over then-national security adviser Michael Flynn’s conversations about U.S. sanctions policy with Russian Ambassador Sergey Kislyak. She was nominated to the diplomatic post when Flynn’s replacement wanted to replace her with another aide.

“I am disappointed that K.T. McFarland has withdrawn from consideration to be Ambassador to Singapore,” Trump said in a Friday afternoon press statement. “K.T. served my Administration with distinction. Unfortunately, some Democrats chose to play politics rather than move forward with a qualified nominee for a critically important post.”

McFarland’s nomination never received a final vote, even though she passed out of the Senate Foreign Relations Committee in September. Sen. Cory Booker, D-N.J. questioned whether she had misled the committee when she denied, in written testimony, knowing about Flynn’s conversations with Kislyak. Court documents related to Flynn’s guilty plea for lying to the FBI, as well as other emails from the Trump transition team, led the Senate to learn that she had been aware of the discussion at the time.

“If this is the case, this is an alarming development, and another example of a pattern of deception on the part of Trump’s closest associates regarding their connections and communications to Russian government officials,” Booker said in December, per the New York Times.

McFarland’s team maintains that she gave an inaccurate answer because she didn’t have access to her emails and calendars from the time, presumably because of special counsel Robert Mueller’s ongoing investigation, and thus had to answer from memory alone.

“One of McFarland’s advisers acknowledged that her brief written response to Booker’s question was poorly worded but said that her answer was taken out of context by Booker and journalists, accusing them of wanting ‘another scalp,’” The New Yorker reported. “When McFarland wrote that she wasn’t ‘aware of any of the issues or events as described above,’ she was referring to Booker’s earlier assertions, not his question about Kislyak, the adviser said. One of McFarland’s friends said that she couldn’t answer questions from senators more thoroughly because lawyers wouldn’t let her.”

McFarland, a former speechwriter for Ronald Reagan, brought some traditional Republican foreign policy ideas to a White House team that had run an iconoclastic campaign. She moderated a panel at the Republican National Convention, that — as she pointed out during the event — was attended by a pair of Trump’s advisers. Her panelists took the opportunity to urge Trump’s team to value the efficacy of U.S. foreign aid and moderate his tone on national security issues.

"If Mr. Trump doesn't already, I would encourage him to read the writings of Teddy Roosevelt, carry a big stick — but speak softly," retired Marine Commandant Gen. James Conway said during the McFarland panel.