Udall, D-N.M., said he would continue listening to debate and seeking information, but he intended to vote against using military force against the regime of Bashar al-Assad.
If America's objective is to save lives, “even a limited military strike isn't the answer,” Udall said in a conference call with New Mexico reporters. He said such an attack would make Assad “more desperate” and in turn endanger more lives.
Udall went from the conference call to the caucus of Senate Democrats, who were to meet with President Obama. Obama wants to use military force in Syria and is trying to persuade Congress to authorize it.
Udall, who voted against the president's plan in a committee hearing last week, said nothing yet had changed his mind.
The prospect of America becoming embroiled in Syria's civil war is not the smartest or best option, Udall said. Rather, he said, cutting off Assad's sources of power make more sense than military action.
One radio reporter told Udall he was outraged by Assad using deadly gas to kill civilians and asked how the United States could hold back, given these widespread attacks. Udall said he shared outrage at the atrocities.
“The question is how you respond,” he said.
He said he did not accept the idea that America should be the world's policeman, especially when all economic and diplomatic options had not been attempted, much less exhausted.
New Mexico's other senator, Democrat Martin Heinrich, on Monday night said he supported military action against Assad, provided that it was limited in scope and would not involve U.S. soldiers fighting in Syria.
Udall offered a different assessment, saying air strikes would not be wise and would only create an environment for more attacks by Assad as he tried to hold his power base.
Udall said a vote by the full Senate likely would be postponed until next week. He said he expected it to be close.
Opposition to the president's plan appears greater in the House of Representatives.
Milan Simonich, Santa Fe Bureau chief of Texas-New Mexico Newspapers, can be reached at 505-820-6898 and firstname.lastname@example.org. Follow him @MilansNMreport on Twitter. His blog is at nmcapitolreport.com.