President Donald Trump's letter to Turkish President Recep Tayyip Erdogan caught the attention of Democratic lawmakers, who quickly compared it to "a joke."

"I don't even know where to start," Rep. Seth Moulton of Massachusetts said to Insider. "It's utterly pathetic."

"An average student at one of America's failing high schools could write a more effective letter than this," Moulton added. "And here we have the president on White House stationary showing the entire world that he has no idea how to negotiate with foreign leaders. And this is his job."

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President Donald Trump's letter to Turkish President Recep Tayyip Erdogan caught the attention of Democratic lawmakers, who quickly compared it to "a joke."

"I don't even know where to start," Rep. Seth Moulton of Massachusetts, a retired Marine Corps officer and a member of the House Armed Services Committee, said to Insider. "It's utterly pathetic."

"An average student at one of America's failing high schools could write a more effective letter than this," Moulton added. "And here we have the president on White House stationary showing the entire world that he has no idea how to negotiate with foreign leaders. And this is his job."

Democratic Rep. Mike Quigley of Illinois also appeared to be flabbergasted with Trump's letter to Erdogan earlier on Wednesday.

"I'll be honest. I saw this online first," Quigley said during a CNN interview. "I actually thought it was a prank, a joke. That it couldn't possibly come from the Oval Office.

"It sounds like ... the president of the United States in some sort of momentary lapse, just dictated angrily whatever was on the top of his head," Quigley added. "These are extraordinarily serious issues, and in an extraordinary dangerous part of the world."

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The letter, which was first published by Fox Business anchor Trish Regan and later confirmed by the White House, was dated October 9, three days after Trump held a controversial phone call with President Erdogan. Following the call, Trump ordered US troops to stand down as Turkey launched a military assault targeting Kurdish forces in northeast Syria.

"Let's work out a good deal," Trump wrote in the beginning of his letter. "You don't want to be responsible for slaughtering thousands of people, and I don't want to be responsible for destroying the Turkish economy — and I will."

"Don't be a tough guy," Trump added. "Don't be a fool! I will call you later."

Trump's decision for a withdrawal drew bipartisan condemnation in the following days, with many lawmakers alleging the US was abandoning its allies against ISIS. Roughly 11,000 Kurds died during the anti-ISIS campaign, and the abrupt decision for the US allies to leave the region caught lawmakers and US military officials by surprise.

Trump defended his decision by downplaying the Kurdish role in the war against ISIS and referring back to his promise for the US troops to leave the Middle East.

During a meeting with lawmakers at the White House on Wednesday, Trump railed against Democrats, who left after he reportedly taunted, "see you at the polls," and described House Speaker Nancy Pelosi as a "third-rate politician."

Speaking to reporters in the afternoon, Pelosi said she responded to Trump's insults during the meeting: "I said, 'I wish you were a politician, Mr. President Trump, then you would know the art of the possible.'"