Two U.S. troops and two American civilians were killed, and three service members wounded, in a suicide bombing attack in the northern Syrian city of Manbij on Jan. 16. ISIS claimed responsibility for the attack, which also killed upwards of 15 civilians, but details were still developing in the hours following the bombing.

WASHINGTON — One of President Donald Trump’s closest allies in Congress criticized the commander-in-chief on Wednesday for statements he says may have emboldened Islamic State militants and led to the deaths of U.S. service members in Syria.

The comments came at the same time that Vice President Mike Pence publicly claimed that ISIS “has crumbled” and “has been defeated” during a State Department event on Wednesday a few miles away from Capitol Hill.

Pentagon officials still have not confirmed details of an explosion in the northern Syrian town of Manbij that claimed the lives of multiple U.S. troops, the first casualties since the White House announced plans to draw down American forces in the region.

Several times in recent weeks, Trump justified the pull-out by saying that ISIS was essentially defeated, rendering the U.S. mission there moot.

Pence echoed that message in his speech, promising an orderly but deliberate withdrawal in coming weeks.

But numerous members of Congress — including usually supportive Republican lawmakers — have expressed doubt over the rapid withdrawal.

Among them is Sen. Lindsey Graham, R-S.C., who during a Senate Judiciary Committee hearing on Wednesday connected the president’s recent comments with the latest deadly attack.

“My concern about the statements made by President Trump is that you set in motion enthusiasm of the enemy we’re fighting,” Graham said. “As they get bolder the people who we’re trying to help are going to get more uncertain.

“Every American wants our troops to come home. But I think all of us want to make sure that when they do come home we’re safe. So I would hope the president would look long and hard of where he’s headed in Syria.”

Graham added that he understands public frustration with the Syria fight but added “we’re never going to be safe here unless we’re willing to help people over there who will stand up against this radical ideology.”

A statement from the White House on Wednesday afternoon expressed sympathy for the loss of the U.S. troops killed in Syria.

“Our deepest sympathies and love go out to the families of the brave American heroes who were killed today in Syria,” the message said. “We also pray for the soldiers who were wounded in the attack. Our service members and their families have all sacrificed so much for our country.”

Officials from Combined Joint Task Force-Operation Inherent Resolve confirmed this week that the U.S. military has increased the frequency of airstrikes in recent weeks as the withdrawal plans have progressed.

Former Defense Secretary Jim Mattis stepped away from his Pentagon leadership post just days after the Syria withdrawal was first reported, and cited concerns about a lack of support for U.S. allies by the Trump administration among the reasons for his departure.