Republicans are crying foul after Ukrainian President Volodymyr Zelenskyy was flown to the battleground state of Pennsylvania, and disparaged former President Donald Trump and his running mate Senator J.D. Vance (R-Ohio).

Zelenskyy is slated to speak at the U.N. General Assembly annual gathering Tuesday and Wednesday of this week, and will then travel to Washington for talks on Thursday with Joe Biden and Kamala Harris.

“My feeling is that Trump doesn’t really know how to stop the war even if he might think he knows how,” he told the New Yorker on Sunday. When asked about Vance, the Ukrainian president dismissed him as “too radical.”

Senator Eric Schmitt (R-Mo.) registered his disapproval on X Monday, calling the situation “unreal.”

“Zelensky is openly campaigning for Democrats in battleground Pennsylvania today some 50 days out from our Presidential election, he wrote.

Former Trump advisor and America First Legal founder Stephen Miller called the situation a “major FEC violation.”

Zelenskyy visited the Scranton Army Ammunition Plant Sunday afternoon, after arriving in a U.S. Air Force C-17.

“The Biden-Harris admin is using military assets to fly a foreign leader into a battleground state in order to undermine their political opponents,” complained Dan Caldwell, public policy advisor at Defense Priorities.

Rep. Matt Cartwright (D-Penn.), who was among those who met with Zelenskyy at the ammo plant, described Zelenskyy’s visit as an “off the charts” and “spine-tingling” moment.

“It was surreal to have President Volodymyr Zelenskyy come here and express his thanks and support for the effort that we’re engaged in here,” Cartwright later told reporters. “It was off the charts in terms of the kind of spine-tingling surreality that I’ve ever experienced.”

During the visit, Zelenskyy and Pennsylvania Governor Josh Shapiro (D) signed artillery shells manufactured to be used in the war.

The Ukrainian president expressed his gratitude to all the employees at the weapons plant, saying their work making bombs helps “ensure that life is protected.”

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

Correction:  Zelenskyy’s interview with Vanity Fair was published on Sunday, but reportedly took place days before his trip to Pennsylvania.