House Speaker Mike Johnson is demanding that Volodymyr Zelensky fire the widely respected diplomat who has represented Kyiv in Washington since 2021 after she arranged for the Ukrainian president to visit a munitions plant in a battleground state with a Democratic governor.

In a letter released by Johnson’s office on Wednesday, the Louisiana Republican accused Ambassador Oksana Markarova of interfering in the ongoing US presidential election by helping set up the trip by Zelensky to the Scranton Army Ammunition Plant in Scranton, Pennsylvania, over the weekend.

During his visit, Zelensky inspected production lines where the 155mm artillery shells used by his country’s forces are being produced. He did so alongside the state’s governor, Josh Shapiro.

While inspecting the plant, he told workers: “It is in places like this where you can truly feel that the democratic world can prevail. Thanks to people like these — in Ukraine, in America, and in all partner countries — who work tirelessly to ensure that life is protected.”

What appears to have irked Johnson is the fact that no Republican officeholder was invited to the plant visit, along with the fact that Shapiro, who was considered a front-runner to be Vice President Kamala Harris’s running mate before she selected Minnesota Governor Tim Walz, is a top surrogate for the vice president.

In his letter, the House Speaker claimed that Markarova enabled Zelensky to interfere in the election because the manufacturing plant “was in a politically contested battleground state” and the tour led by Shapiro “failed to include a single Republican because — on purpose — no Republicans were invited.”

“The tour was clearly a partisan campaign event designed to help Democrats and is clearly election interference. This shortsighted and intentionally political move has caused Republicans to lose trust in Ambassador Markarova’s ability to fairly and effectively serve as a diplomat in this country,” he wrote, adding that the veteran diplomat “should be removed from her post immediately.”

Zelensky, who is in the US to attend the UN General Assembly this week, also irked Republicans by criticizing former President Donald Trump in an interview with the New Yorker.

He said the ex-president, who was impeached for attempting to blackmail the Ukrainian leader into announcing a fake investigation into Joe Biden when he was a candidate for president in 2019, “doesn’t really know how to stop the war even if he might think he knows how.”

Trump has frequently claimed, without evidence, that he could end the nearly three-year-old war “in 24 hours” by forcing Zelensky to make some sort of deal with Russian President Vladimir Putin, a known ally of the ex-president.

At a rally on Monday, he claimed Zelensky wants Democrats to win the election “so badly” and repeated the claim the next day.

Numerous Republicans have opposed US assistance to Ukraine since the war began in 2022, with some repeating Russian propaganda about Zelensky during official House proceedings.

Zelensky is set to visit Washington on Thursday, where he is scheduled to meet with Senate leaders from both parties as well as President Biden and Vice President Harris.