President Trump's sudden pronouncement that U.S. troops in Afghanistan "should" be home by Christmas will make the already sensitive negotiations with the Taliban more difficult, U.S. officials told Fox News on Thursday.

In the deal the Trump administration signed with the Taliban in February, all U.S. troops will leave Afghanistan by May 2021 if conditions are met. The conditions include that there will be no attacks against U.S. forces.

TRUMP SAYS US TROOPS IN AFGHANISTAN WILL BE HOME BY CHRISTMAS

"We should have the small remaining number of our BRAVE Men and Women serving in Afghanistan home by Christmas!" Trump tweeted late Wednesday.

The Taliban said in a statement on Thursday that they welcomed the president’s announcement.

However, the president appeared to have gotten ahead of his negotiators and his National Security team. Trump's tweet came hours after his national security adviser, Robert O’Brien, said the U.S. would reduce its forces to 2,500 by early next year.

U.S. officials told Fox News that the sudden pronouncement, which appeared timed to help Trump in the presidential election, will make it harder for his negotiators and the Afghan government, who are currently in tough talks with the Taliban in Doha, Qatar.

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Several officials close to the negotiations said the declaration may have even jeopardized the delicate talks. Counterterrorism officials said this may lead to a victory for the Taliban, and the collapse of the Afghan government and a "major shot of adrenalin" to the global jihadist movement.

The timeline agreed to by U.S. negotiators had May of next year as a possible timeline for all U.S. troops to leave Afghanistan, or for some to remain as a counterterrorism force if the Afghans agree.

Trump has previously said his administration would not make announcements about troop movements to keep America’s enemies in the dark.

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"We will not talk about numbers of troops or our plans for further military activities," Trump said in remarks on the strategy in Afghanistan and South Asia in 2017. "Conditions on the ground — not arbitrary timetables — will guide our strategy from now on. America’s enemies must never know our plans or believe they can wait us out."

Fox News' Lucas Tomlinson contributed to this report.