Former President Donald Trump, left, and candidate Vivek Ramaswamy.
CNN  — 

Donald Trump lashed out at GOP rival Vivek Ramaswamy for the first time on Saturday, arguing on social media he is “not MAGA” as the former president and his campaign have grown increasingly frustrated with what they claim are Ramaswamy’s disingenuous campaign tactics, Trump campaign advisers told CNN.

“Vivek started his campaign as a great supporter, ‘the best President in generations,’ etc. Unfortunately, now all he does is disguise his support in the form of deceitful campaign tricks,” Trump wrote on Truth Social Saturday.

“Very sly, but a vote for Vivek is a vote for the ‘other side’ — don’t get duped by this. Vote for ‘TRUMP, don’t waste your vote! Vivek is not MAGA. The Biden Indictments against his Political Opponent will never be allowed in this Country, they are already beginning to fall! MAGA!!!” he added.

This is the first and most aggressive attack on Ramaswamy the former president has issued, which comes after a series of comments and posts Ramaswamy made that have angered Trump and his team, Trump’s advisers said. Ramaswamy had previously stayed away from bashing Trump, instead often praising him on the campaign trail.

Ramaswamy posted a photo to X, formerly known as Twitter, on Saturday posing with supporters donning “Save Trump, vote Vivek” T-shirts, which showed a picture of Trump’s mug shot from when he was processed in Georgia at the Fulton County jail in August.

The post, which was shown to Trump, “infuriated” him, one adviser told CNN, noting the former president feels Ramaswamy has been working to undercut his candidacy while falsely painting himself as a Trump supporter.

Trump and his campaign were also annoyed with an interview Ramaswamy gave to NBC News and The Des Moines Register earlier this month, during which he repeatedly described Trump as “wounded.”

“They don’t have on me what they have on him,” Ramaswamy said, arguing he is better positioned to implement Trump’s agenda.

“He’s been making slights at the former president and we have noticed,” another adviser told CNN. “If you poke the bear, the bear will bite back.”

Trump’s team insisted they have not seen anything in the polls to indicate Ramaswamy was gaining on Trump in Iowa, and this response was solely based on Ramaswamy’s recent comments and posts.

Trump’s campaign is hoping to win Iowa by record margins to set the tone for the primary season and stunt any momentum from his rivals. And for a campaign that has developed a ground game strategy focused on turning out as many caucus-goers as possible — every vote counts, particularly as cold weather threatens anticipated turnout on Monday.