INDIANOLA, Iowa — Vice President Joe Biden, speaking to a decidedly antiwar audience in Iowa on Sunday, played down the Obama administration’s pledge to use military force to rid Syria of chemical weapons.
Biden, weighing a run for president in 2016, instead touted the US-Russian diplomatic proposal for Syria to relinquish its chemical arsenal under international supervision.
‘‘We’re going to the United Nations with a resolution this week that will in fact call on the United Nations of the world to put pressure on Syria to have the confiscation and destruction of all those weapons,’’ Biden told hundreds of Iowa’s most devout Democrats at Senator Tom Harkin’s annual steak picnic and fall fund-raiser.
Biden touched only lightly on the administration’s continued insistence that “there are consequences should the Assad regime not comply.”
National public opinion polls show a military strike on Syria is unpopular, especially with Democrats.
The vice president worked to stoke hope that the diplomatic solution would work. Making the administration’s first trip outside Washington since Obama’s speech to the nation Tuesday, Biden said Obama ‘‘is the reason the world is facing up finally, finally to this hideous prospect of this largest stockpile of chemical weapons.’’
There was no applause for his Syria comments from the audience, supporters of Harkin, a veteran Democrat popular with his party’s antiwar activists.
But listeners rose to their feet and cheered loudly when Biden ticked through the economic gains the country has made since Obama took office, improvements the vice president could benefit from, should they continue, if he runs for president in 2016.
Biden praised Harkin as the ‘‘conscience of the Senate,’’ and the senator also raised hope the US-Russian proposal would resolve the Syria issue.
‘‘We didn’t lose one American life,’’ Harkin said, in introducing Biden. ‘‘That’s leadership, folks, that’s leadership.’’
The hopeful tone in Biden’s and Harkin’s remarks came despite Obama’s warning in an interview Sunday, ‘‘if diplomacy fails, the United States remains prepared to act.’’
Obama, who rode an antiwar wave to victory in Iowa’s 2008 presidential caucuses, had proposed limited air strikes in Syria in response to what the United States says was a chemical weapons attack last month that killed more than 1,400 people.
His administration blames the government of President Bashar Assad.
Some Democrats who were in attendance said that even if the president later orders a military strike, Obama will not have rushed to war.
‘‘At the end of the day, if that terrible option has to be played out, this crowd, what they voted for Barack Obama to do, what they wanted, was this kind of leadership: smart, thoughtful, not reactionary,’’ said Sue Dvorsky, former state party chairwoman.
His own party cool to a military strike, Obama has struggled to win support for military action from members of Congress, whose constituents have endured more than a decade of war.