Former CIA Director and retired US Army Gen. David Petraeus said today the US betrayed its longstanding ally in its fight against ISIS, the Syrian Kurds, by withdrawing US forces from the northern part of the country.

Petraeus, who previously oversaw military operations in Afghanistan and Iraq, criticized President Trump's decision to withdraw US forces from northern Syria on CNN's "State of The Union." 

"Well, I think we have abandoned our Syrian Kurdish partners. They took over 10,000 losses as the defeat of Islamic State was carried out," he told CNN's Jake Tapper. "The elimination of the caliphate that ISIS had certainly with our advice and assistance and enabling and then very suddenly, this is not a phased deliberate plan withdrawal, this is a very sudden exit."

Petraeus also took issue with Trump's previous statement that leaving northern Syria would halt an "endless war." 

"This does not end an endless war. It probably prolongs it because this gives ISIS an opportunity for a resurgence," Petraeus said. "This is not a strategic success."

Some background: Petraeus' comments come amid backlash over Trump's decision to withdraw US forces from northern Syria. Vice President Mike Pence announced Thursday that he and Turkish President Recep Tayyip Erdogan had reached an agreement on a ceasefire in the country. 

The move has received bipartisan criticism and concern that Trump's actions could lead to a resurgence of ISIS.