WASHINGTON — The Senate on Thursday failed to overturn President Donald Trump's veto of legislation that would have ended U.S. military assistance for the Saudi-led war in Yemen against Iran-backed rebels, but lawmakers promised to keep close watch on the administration's ties with the kingdom.

While the 53-45 vote to override fell well short of the required two-thirds, passage of the resolution in April was an unprecedented rebuke of Trump's foreign policy and a milestone for Congress, which invoked never-before-used powers in an effort to halt foreign military activity. The United States is providing logistical support and intelligence-sharing for a war that has killed thousands of civilians and left millions more on the brink of famine.

In explaining his veto last month, Trump said the Yemen resolution was a "dangerous attempt to weaken my constitutional authorities, endangering the lives of American citizens."

To one of the resolution's sponsors, Sen. Bernie Sanders, the action on Capitol Hill showed that "after years of abdicating that responsibility, Congress stood up in the Senate and in the House and said: You know what, Mr. President? You do not have the power to get U.S. troops involved in a war that we did not vote upon. And that is a big deal." Sanders, a Vermont independent, is seeking the Democratic nomination for president in 2020.

The push to end American involvement in the war gained strength in Congress last year after Saudi agents killed Jamal Khashoggi, a commentator who had lived in the U.S. and written critically about the kingdom. Lawmakers criticized Trump for not condemning Saudi Arabia's role strongly enough and they urged new penalties against the American ally. The administration has forged close ties with the Saudis as it seeks to further isolate Iran.

Despite the veto remaining intact, some lawmakers pledged continued scrutiny of U.S.-Saudi ties.

Sen. James Risch, chairman of the Senate Foreign Relations Committee, said he was considering legislation to "put the relationship on the right trajectory."

"Like many of us here today, I'm dissatisfied with the state of the U.S.-Saudi relationship. Indeed, while Saudi Arabia has long been a bulwark of our Middle East policy, there is a growing gap in U.S.-Saudi relations," said Risch, R-Idaho. "Frankly, aspects of Saudi Arabia's behavior are cause for serious, serious concern."

Risch said his committee is taking a "comprehensive look" at the alliance and trying to develop legislation that can "address concerns on both sides of the aisle and actually become law."

Sen. Chris Murphy, D-Conn., one of the sponsors of the resolution, said opposition to the war in Yemen is "about sending a message to Saudi Arabia" and about "getting the blood off of our hands."

"The United States should never willingly be a part of a bombing campaign that results in this kind of starvation," he said, gesturing to a photo of an emaciated Yemeni boy.

The Pentagon said continued support of the coalition is in the U.S. interest because it helps American allies push back against Iranian aggression in the region.