Davenport, Ill.-President Donald trump has sold out United States allies and given ISIS “new life” by withdrawing troops from Syria, former Vice President Joe Biden said Wednesday.

Biden, who is seeking The democratic presidential nomination in 2020, used a speech in Iowa to criticize several aspects of trump’s foreign policy, including a trade war with China and his withdrawal from the Iran nuclear deal.

Trump is a “total failure” and “the most reckless and incompetent commander-in-chief we’ve ever had,” Biden said.

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But he retained his harshest words on trump’s decision earlier this month to withdraw U.S. military forces from Northern Syria. Turkey subsequently invaded the country, including territory held by the Kurds, who were U.S. allies in the fight against ISIS.

“The events of last week in Syria have brought devastating clarity to how dangerous it is to our national security, to our leadership around the world, and to the lives of our brave men and women serving in uniform,” Biden said, according to prepared remarks.

The decision to withdraw from Syria, Biden said, created a humanitarian crisis and gave ISIS “new life, forcing the Kurds to defend against Turkey rather than fight the remnants of ISIS.”

“These brave Kurdish and Arab forces paid a high price, and more than 10,000 people sacrificed their lives,” Biden said, according to prepared remarks. “And then trump sold them.”

Trump backed his decision.

“This is not our problem,” the President told reporters Wednesday as Vice President Mike Pence and Secretary of state Mike Pompeo prepared to travel to Turkey to try to negotiate a ceasefire and avoid a humanitarian crisis on the Syrian border.

Biden also used the speech to highlight the Obama administration’s efforts to combat ISIS.

“The Obama and Biden administrations worked with partners in and with Syria, and just a few hundred Americans supported tens of thousands of local fighters to fight ISIS on the ground,” Biden said. “Our strategy was so successful that it turned out that trump’s secret plan to defeat ISIS is to just keep doing what we were doing-until last week.”

Trump has faced bipartisan criticism for the withdrawal, with the US House of representatives voting overwhelmingly on Wednesday afternoon to condemn the move.