Trump offers renewed support for Saudi-led bombing of Yemen
Democrats and Republicans have butted heads with Trump over continued US military support for the Saudi-led coalition intervening in the Yemeni war.
The two parties reintroduced the legislation dating from 1973 two weeks ago, aimed at limiting the president's power to commit the US to armed conflict.
The move sent a clear message to Riyadh and the White House about both the humanitarian crisis in Yemen and the killing of US-based journalist Jamal Khashoggi.
Trump's administration stated the measure was inappropriate as the US has "only" provided aircraft refuelling, intelligence and targeting assistance to Saudi Arabia, and not combat troops.
Many members of Congress were angered after the White House failed to meet a legally mandated deadline on Friday to submit a report to Congress identifying those responsible for the Saudi state-sanctioned killing of dissident journalist Jamal Khashoggi.
"A US resolution would have been a welcome condemnation and a strong message to Riyadh about the humanitarian disaster in Yemen," said Sana al-Uqba, The New Arab's Yemen analyst.
"Trump's decision to veto these efforts highlight, once again, that he is not willing to contribute to global efforts to end the conflict."
Saudi Arabia, considered by Trump an important regional ally, spearhead a coalition fighting Iran-backed Houthi rebels in Yemen. But Riyadh has faced increasing scrutiny as the conflict developed into what the UN called the world's worst humanitarian crisis, with tens of thousands dead and millions of people at risk of mass starvation.
The war between the Houthis and troops loyal to the internationally recognised government escalated in March 2015, when President Abd Rabbo Mansour Hadi fled to Saudi Arabia and the Riyadh-led coalition intervened with a devastating bombing and boots-on-the-ground campaign.