WASHINGTON — The U.S. Senate was poised to make a historic rebuke of President Donald Trump’s foreign policy after voting Wednesday to advance a resolution that could halt American military support for Saudi Arabia’s ongoing war against Iranian-backed rebels in Yemen.

The final vote on the resolution is expected as early as Thursday, after the Senate voted 60-39 to open debate. The strong vote is a signal that the measure — which is sponsored by Sens. Bernie Sanders, I-Vt.; Mike Lee, R-Utah, and Chris Murphy, D-Conn., but opposed by Senate Majority Leader Mitch McConnell and most Republicans — may pass the Senate.

McConnell, R-Ky., urged lawmakers to vote for an alternative measure from Senate Foreign Relations Committee Chairman Bob Corker, R-Tenn., which condemns Saudi Crown Prince Mohammed bin Salman for the Oct. 2 killing of U.S.-based Saudi journalist Jamal Khashoggi.

“I think every single member of this body shares grave concerns about the murder of Khashoggi and wants accountability,” said McConnell, R-Ky. “We also want to preserve a 70-year partnership between the United States and Saudi Arabia, and we want to ensure it continues to serve American interests and stabilizes a dangerous and critical region.”

Both Democrats and some Republicans, including Corker, have questioned whether the Trump administration took a strong enough stance against the Saudis following reports that the CIA had concluded that the Saudi Crown Prince ordered Khashoggi’s murder.

The Sanders-Lee resolution is seen as a means to send a message to Saudi Arabia over Khashoggi, if not a way to assert Congress’ authority to end U.S. complicity in a mushrooming humanitarian crisis.

In a Senate floor speech Wednesday beside a large photo of an emaciated child, Sanders pointed to the deaths of Yemeni civilians through the Saudi-led coalition’s indiscriminate use of American made weapons and the deaths of 85,000 children by starvation in the three-year-old Yemeni civil war.

“In August, there was an American-made bomb that obliterated a school bus full of young boys, killing dozens and wounding many others," Sanders said. "A CNN report found evidence that American weapons have been used on a string of such deadly attacks on civilians since the war began.”

Since 2015, the United States has provided limited support to member countries of the Emirati and Saudi-led coalition, including intelligence sharing, logistics, and, until recently, aerial refueling, according to the White House.

Corker and the White House have argued the War Powers Resolution is being misapplied because the U.S. is not involved in hostilities as defined by the War Powers Resolution of 1973. Invoking it now, Corker said in a Senate floor speech, might have unintended consequences for American military cooperation around the globe.

“We have operations throughout northern Africa where we’re working with other governments on intelligence to counterterrorism, and we’re doing refueling activities in northern Africa now,” Corker said. “It concerns me that if we use this [legislative] vehicle, we may have 30 or 40 instances where this vehicle might be used to do something that really should not be dealt with by the War Powers Act.”

If the resolution passes the Senate, it will be stymied in the Republican-controlled House. The House moved Wednesday to block a floor vote through January on a corresponding measure by attaching it to a rule for debating an unrelated farm subsidies bill. (The rule passed 226-169, with members of both parties crossing sides.)

The sponsor of that resolution, Rep. Ro Khanna, D-Calif., said that leadership in both parties opposed his efforts, when he began two years ago and most lawmakers didn’t know the U.S. was actively involved in aiding the Saudi bombing of Yemen.

“We have another generation growing up in Yemen seeing American missiles take the lives of their family members,” he said. “That’s not making us any safer.”

Democrats are likely to be more aggressive on Saudi issues when they take the House majority in January. The top Democrat on the House Intelligence Committee, California Rep. Adam Schiff, said he intends to lead a “deep dive” into Saudi Arabia and Yemen. Democratic Rep. Eliot Engel of New York, the likely incoming chairman of the House Foreign Affairs Committee, said he would hold hearings on Saudi Arabia early next year.

Earlier this month, Trump sent Secretary of State Mike Pompeo and Defense Secretary James Mattis to Capitol Hill to plead with the Republican-led Senate not to embrace the Sanders-Lee resolution, saying it would do “immense damage” to U.S. interests in the region and short-circuit diplomatic efforts to end the war.

Pulling back that support would also do nothing to alleviate a spiraling humanitarian crises that has been generated by the war there, Pompeo warned lawmakers during a briefing, and it would be to Iran’s advantage.

Trump has emphasized the importance of strong Saudi relations for the benefit of the U.S. economy. Though Trump has been criticized for exaggerating the size of arms deals he’s shepherded, Saudi Arabia has purchased $10.8 billion in U.S. arms between 2010 and 2017, according to data compiled by SIPRI.

The Associated Press contributed to this report.