WASHINGTON (Reuters) - The Republican-led U.S. Senate on Wednesday approved a resolution seeking to end U.S. support for the Saudi Arabia-led coalition in the war in Yemen, in a rebuke of President Donald Trump’s policy toward the kingdom.

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The vote was 54-46 in the Senate, more than the 51 needed to pass in the 100-member Senate, as seven Republicans joined Democrats in backing the measure. The war powers resolution seeks to end any U.S. military involvement in the conflict, including providing targeting support for Saudi air strikes, without authorization from Congress.

The four-year-long civil war in Yemen, which pits the Saudi-led coalition against Houthi rebels backed by Iran, has killed tens of thousands of people and spawned what the United Nations calls the world’s most dire humanitarian crisis, with the country on the brink of famine.

Backers of the resolution, including a handful of Trump’s fellow Republicans as well as Democrats, argued that U.S. involvement in Yemen violates the constitutional requirement that Congress, not the president, should determine when the country goes to war.

“We’re helping a foreign power bomb its adversaries in what is undoubtedly, irrefutably, a war,” said Republican Senator Mike Lee, who sponsored the resolution, urging a ‘yes’ vote.

The Yemen vote could be only the first of two major setbacks for Trump this week, as senators are due to vote tomorrow on a resolution disapproving of his use of his emergency powers to pay for a wall on the border with Mexico, even though Congress has not approved it.

The resolution must still be approved by the House of Representatives to be sent to the White House, which said earlier on Wednesday that Trump plans a veto. It would be the first of his two-year-long presidency.

MESSAGE TO TRUMP - AND RIYADH

Democrats and Republicans reintroduced the resolution two weeks ago as a way to send a strong message to Riyadh - and to Trump - about the humanitarian disaster in Yemen. Many lawmakers also want to push Trump to demand a stronger response from the Saudi government to the murder of Saudi journalist Jamal Khashoggi at a Saudi consulate in Turkey in October.

Trump has held back on criticizing Saudi Arabia, calling them an important strategic ally and counterbalance to Iran in the region. He has also touted Saudi purchases of U.S. defense equipment as a generator of American jobs.

Resolution opponents argued that support for the Saudi-led coalition is not an appropriate use of the war powers act limiting the president’s ability to send troops into action, because U.S. forces are not actively engaged in fighting.

Some also contended that stopping U.S. support would help Iran, and potentially prolong the conflict by ending Washington’s ability to influence Saudi Arabia and the United Arab Emirates, a partner in the conflict, to pursue a sustainable political settlement.

“We need to stay engaged with the limited engagement that we have,” said Senator Jim Risch, the Republican chairman of the Foreign Relations Committee. He also said the resolution “sets a bad precedent” because the United States is not directly involved in Yemen.

The Senate had approved the war powers resolution in December, during the last Congress, the first time such a measure had passed the chamber. But Republicans, who controlled the House until January, did not let it come up for a vote.

With the Democrats in control, the House passed its own version of the resolution in February, but a procedural issue meant the House must vote on the Senate’s version of the measure.

Overcoming a veto would require two-thirds majorities in both the Senate and House, more votes than it has garnered so far.