President Donald Trump on Saturday defended his decision to withdraw U.S. forces from northern Syria before a crowd of evangelicals, as many in the religious community have condemned the president's move that left Kurdish Christians open to Turkey's military offensive.

Trump acknowledged that his choice was unpopular, describing himself as being on an "island of one," but argued that it was time to bring U.S. soldiers home from an "endless war."

"I don't think our soldiers should be there for the next 50 years guarding a border between Turkey and Syria when we can't guard our own borders at home," Trump said, garnering muted applause from the audience. "I don't think so."

The president spoke as Turkey's military made gains in its offensive against Kurdish fighters, a close U.S. partner in combating the Islamic State. Turkey launched its operation into Syria days after Trump and Turkish President Recep Tayyip Erdogan spoke by phone and the White House announced that the United States would not stand in Turkey's way.

Trump saved his remarks about Syria until the end of his hour-and-20-minute speech to the Values Voter Summit in Washington, where he delivered a stripped-down version of his campaign-rally speech with its familiar targets and complaints.

Trump railed against the "radical left," repeated his claim that he thinks House Speaker Nancy Pelosi, D-Calif., "hates this country" and called Intelligence Committee Chairman Adam Schiff, D-Calif., "crooked as hell."

He mocked Schiff's appearance, calling him "pencil neck," and told a woman in the audience that she "would not be impressed with him physically."

He also criticized Somali-born refugee Rep. Ilhan Omar, D-Minn., as "anti-Semitic" and described the Democrats as "waging war on everyone in this room."

The "radical left" wants to "indoctrinate our children," Trump said. "They resent and disdain faithful Americans. Given the chance, they'd use every instrument of government power to try and shut you down."

Trump's support among white evangelicals has been unflagging since he won 80 percent of their vote in 2016. But his recent decision to pull back troops from northern Syria has exposed some fractures in that reliable base.

Pat Robertson, a longtime Trump supporter and founder of the Christian Broadcasting Network, said Monday that Trump "is in danger of losing the mandate of heaven" for betraying the Kurds.

Before Trump spoke, Cissie Graham Lynch, the granddaughter of the late Rev. Billy Graham, offered prayers for the Kurdish people. Then she prayed for Trump and Vice President Mike Pence.

When Trump took the stage, Andrew Brunson, a pastor who had been a prisoner in Turkey for two years and was accused of committing crimes on behalf of Kurdish fighters, prayed over him.

"I ask that you give the president supernatural discernment to know who is trustworthy and who is not. Bring into the light all deception and intrigue. Expose and reverse the plans of those who would harm President Trump and this nation," Brunson said, his hand on Trump's shoulder.

Yet some of the harshest criticism of Trump over his Syrian pullout has come from members of his Republican Party, including his closest congressional allies.

In a tweet, Rep. Dan Crenshaw, R-Texas, seized on the president's complaint about the United States being stuck in an "endless war."

"Situation when we were there: relative peace. We leave: -Turkey attacks our Kurdish allies -shoots artillery at US troops -bombs a prison where ISIS fighters already escaped. -ISIS car bomb in Qamishli. That's just day one. Which scenario looks more like an endless war?" Crenshaw said.

Trump sought to reassure the crowd that Turkey would face "swift, strong and severe economic sanctions" if it does "not meet their commitments, including the protection of religious minorities." He also announced $50 million in emergency financial assistance to Syrian groups that support ethnic and religious victims of this conflict.

Earlier in his remarks, Trump spent considerable time lashing out at the House impeachment inquiry, arguing that it is for "horrible, horrible crimes" and labeling it a "witch hunt."

He also rehashed the confirmation of Supreme Court Justice Brett Kavanaugh, telling the crowd that the accounts of sexual assault were "phony stories about him. They were made up. Just like they are made up about me and other people."

Christine Blasey Ford alleged that Kavanaugh had sexually assaulted her when they were teenagers. Kavanaugh has denied the accusation.