Democratic presidential candidate Sen. Bernie Sanders, I-Vt., said on Tuesday that he doubts the Trump administration’s rationale for why the U.S. killed Iranian military commander Qassem Soleimani in a targeted strike.

The White House and top officials claim that evidence of an imminent national security threat motivated the president’s controversial decision to target Soleimani in a drone strike Friday.

“We haven’t seen that evidence. Frankly, I doubt that evidence is there,” Sanders said in an interview with PBS NewsHour anchor and managing editor Judy Woodruff. He compared President Donald Trump’s messaging on Iran to the George W. Bush administration’s justification leading up to the Iraq War in 2003, which Sanders strongly opposed.

“A war with Iran would likely be even worse,” he said, adding that he will push for the U.S. to solve international disputes diplomatically “in this instance and in other instances.”

The strike on Soleimani has drawn criticism from some lawmakers and national security experts who argue the move has pushed the U.S. to the brink of war with Iran. Some Republican members of Congress have applauded the killing as a necessary move.

On Tuesday night, the Pentagon confirmed that Iranian forces had fired missiles at two Iraqi air bases where U.S. troops were housed.

When asked whether he thought Trump had committed a war crime by killing Soleimani, Sanders responded that killing top officials of a foreign government sends a message to countries throughout the world that the U.S. could do something similar again.

“I think the world and this country is sick and tired of endless wars that have cost us trillions of dollars while our infrastructure is collapsing, our health care system is dysfunctional,” he said, adding that instead, “We have to deal with climate change and invest heavily in transforming our energy system.”

More highlights from the interview: