Susan Rice, former national security adviser to Barack Obama, said Donald Trump's decision to pull US troops from Syria is "bats--- crazy."

In a shock move on Sunday, Trump announced that the US would pull 1,000 US troops working with the Syrian Democratic Forces (SDF) as part of the US-Kurdish coalition beating back ISIS since 2014.

Critics slammed Trump on Monday for abandoning the Kurds, who now face an invasion from Turkish troops, and were instrumental in taking down ISIS.

Rice, appearing on CBS' "The Late Show with Stephen Colbert" said: "They have sacrificed immensely and we basically just said to them 'see ya' and let the Turks, who are like the hungry wolf trying to kill the lamb, go for it."

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Susan Rice, former national security advisor to Barack Obama, says Donald Trump's decision to pull US troops from northern Syria is "bats--- crazy."

On Sunday, Trump said US troops would abandon the joint offensive against ISIS with Kurdish Syrians, known as the Syrian Democratic Forces (SDF,) in place since 2014. The troops number 1,000, according to The New York Times.

"I woke up this morning to hear that news, and as I do it seems like six days a week, I just put my head in my hands," Rice said on CBS's "The Late Show with Stephen Colbert" on Monday.

"This is bats--- crazy."

—The Late Show (@colbertlateshow) October 8, 2019

Speaking on Monday night, Rice said the defeat of ISIS in Syria has as much, if not more, to do with the Kurds, as it does the US.

"These are the people who for the last four years have been fighting on our behalf with our equipment to defeat ISIS."

"And they have done it with enormous efficacy and they have sacrificed immensely and we basically just said to them 'see ya' and let the Turks, who are like the hungry wolf trying to kill the lamb, go for it," she said.

Rice was national security adviser from 2013 to 2017 during the Obama administration. REUTERS/Jonathan Ernst

Rice, who advised Obama on the Syrian conflict from 2013 to 2017, was not alone in airing her exasperation.

US politicians from both sides of the House, foreign policy experts, and counter-terrorism watchers have unanimously condemned the move, citing two likely outcomes.

Read more: Here are the 5 major players that will feel the impact from Trump's decision to withdraw troops from Syria

The first is that Turkey, long fearing Kurdish incursion, will press its advantage and invade the civil war-ravaged country. The US' presence acted as a buffer between the two factions, but experts say Turkey will move into Syria, and repatriate the two million Syrian refugees in Turkey.

A White House statement following a phone call between Trump and Turkish President Recep Tayyip Erdogan on Sunday said: "Turkey will soon be moving forward with its long-planned operation into northern Syria."

Following criticism on Monday, Trump warned he would demolish Turkey's economy if it goes "off-limits" with the SDF in northern Syria.

The second outcome is that the now-weakened SDF may struggle to prevent a resurgence of ISIS in northern Syria.

SDF spokesman Kino Gabriel told The Washington Post on Monday: "We are very disappointed. I don't think we will be able to concentrate on fighting Daesh."

Read more: Republicans and former US officials rip into Trump for abandoning the Kurds in Syria

Republican Sen. Lindsey Graham, a long time Trump ally, said the "shortsighted and irresponsible" decision "virtually reassures the reemergence of ISIS."

The damaged Roman amphitheater in the ancient city of Palmyra in central Syria, March 3, 2017. STRINGER/AFP/Getty Images

The SDF says it lost more than 10,000 fighters in the course of the ISIS conflict.

Read more: Trump defended his controversial decision to pull US forces out of Syria in a rambling tweetstorm

The Syrian Democratic Coalition, the political wing of the SDF, lamented the president's decision in a statement.

"Our brave men and women with the Syrian Democratic ­Forces have just won a historic victory over the ISIS 'caliphate,' a victory announced by President Trump and celebrated across the world."

"To abandon us now would be tragic."