Turkish President Recep Tayyip Erdoğan responded to an extraordinary letter from President Donald Trump — warning him not to “be a tough guy” by invading Syria — by throwing it in the trash and invading Syria anyway, Turkish officials said Thursday.

The Turkish leader’s dismissive response to the Oct. 9 letter doesn’t bode well for Vice President Mike Pence, who is in Ankara today to try to persuade Erdoğan to halt his assault on the Kurds.

In the letter, sent a few days after Trump began withdrawing troops from northern Syria but before Erdoğan launched his cross-border assault, Trump urged his Turkish counterpart to “work out a good deal” to avoid a military operation against the Kurds.

“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,” he wrote.

“History will look upon you favorably if you get this done the right and humane way. It will look upon you forever as the devil if good things don't happen. Don’t be a tough guy. Don’t be a fool!”

It concluded: “I will call you later.”

The language in the letter was so unpresidential that when it leaked, there were doubts it could be genuine. Media outlets scrambled to get confirmation from the White House, and some thought it was a joke by The Onion. Even Kremlin spokesman Dmitry Peskov told a press conference that it was “highly unusual.”

“You don't often encounter such language in correspondence between heads of state,” he said.

But the White House confirmed it was legitimate.

On Thursday, Turkish officials said Erdogan had responded to Trump’s letter by throwing it in the trash.

“The date on the letter is 9 October, the same day we began Operation Peace Spring,” one official told Middle East Eye. “Our president gave the best response by launching the operation on the same day at 4pm.”

The letters’ threatening tone has caused outrage in Turkey at a sensitive time, as Pence and Secretary of State Mike Pompeo hold emergency talks with Turkish officials to try to persuade them to halt the invasion. Former Turkish prime minister Ahmet Davotoglu tweeted that “the Turkish nation and state were offended” by Trump’s letter, and said all meetings with U.S. officials should be cancelled in response.

Ahead of the talks Thursday, a Turkish official told Reuters that negotiating with the Kurds or halting the military operation were “not on the agenda.” Erdogan signalled Wednesday that he wouldn’t be dissuaded, telling Turkish lawmakers in he would not halt unless Kurdish fighters “lay down their arms ... destroy all their traps and get out of the safe zone that we have designated.”

Trump has vigorously defended his call to withdraw U.S. troops from northern Syria, which critics — including many from his own party — say effectively gave Turkey a greenlight to invade.

The offensive, now in its ninth day, has unleashed brutal violence on the Kurds, a key ground partner in the fight against ISIS. It has also ceded influence in the Syrian conflict to the Assad regime and its Russian backers, and threatened to lead to the release of thousands of Islamic State fighters in Kurdish custody.

Despite his ongoing efforts to get Erdogan to call off the offensive, which has created a humanitarian crisis for the 160,000 civilians who have fled their homes, Trump boasted Wednesday that his troop withdrawal was “strategically brilliant.”

"It's not our border. We shouldn't be losing lives over it,” he said. “Our soldiers are totally safe.”

But that didn’t wash with U.S. lawmakers. Sen. Lindsey Graham (R-S.C.), an ally of the president, slammed Trump for his comments, which he said “completely undercut” Pence’s negotiating position in Ankara.

And in a rare bipartisan rebuke, 129 Republicans in the House of Representatives joined Democrats to broadly condemn Trump’s troop withdrawal, and call on Erdogan to immediately cease the operation against the Kurds.

On Thursday, Kurdish authorities called for the establishment of a humanitarian corridor to evacuate civilians from Ras al-Ain, a key border town under heavy Turkish assault. Meanwhile, the forces of Syrian President Bashar al-Assad rolled into the strategic border town of Kobane after striking a deal with the Kurds to help them repel the Turkish aggression.