UPDATE 3-U.S. Senate rebukes Trump over wall but he vows veto

The U.S. Senate passed a proposal on Thursday to terminate President Donald Trump's declaration of an emergency at the southern border, with 12 Republicans defying the president, and Trump vowing a veto. The 59-41 vote marks the second Senate rebuke of Trump in two days. Senators on Wednesday approved a resolution seeking to end U.S. support for the Saudi Arabia-led coalition in the war in Yemen, rejecting Trump's policy toward the kingdom.

During the first two years of his term, the Republican-led Congress mostly accommodated Trump, who has not yet used his veto pen. With the emergency declaration, Trump was seeking an alternative way to get billions of dollars for the wall after Congress declined to give him funding.

Senate Majority Leader Mitch McConnell had urged his fellow Republicans to defeat the measure, which was passed in February by Democratic-controlled U.S. House of Representatives. Trump had tweeted on Thursday that a vote for the resolution by Republican senators would be vote for Democratic House Speaker Nancy Pelosi as well as "Crime and the Open Border Democrats!"

Republicans who defected by supporting the measure to end the emergency declaration are worried that presidents - including future Democratic ones - could usurp the power of Congress to fund the government and use the tactic to pass their own pet programs. (Reporting by Amanda Becker and Richard Cowan; additional reporting by Susan Cornwell, Doina Chiacu, Lawrence Hurley and Susan Heavey; editing by Jeffrey Benkoe and Bill Trott)