By Mark Felsenthal
WASHINGTON (Reuters) - Americans' opposition to a U.S. military strike against Syria is increasing as they learn more about the Arab nation's alleged use of chemical weapons, according to a new Reuters/Ipsos poll that shows the challenge President Barack Obama faces in seeking congressional approval for military action.
The poll, conducted September 5 to 9, indicated that 63 percent of Americans opposed intervening in Syria, up from 53 percent in a survey that ended August 30. That was a week after the August 21 chemical attack in a Damascus suburb that U.S. officials say killed more than 1,400 adults and children.
Meanwhile, support for a U.S. intervention in Syria has declined, the poll found. About 16 percent of Americans surveyed said the United States should get involved - down from 20 percent on August 30.
And even if it's proven that Syrian President Bashar al-Assad's troops used chemical weapons against fellow Syrians, only 26 percent of Americans said the United States should intervene. About 52 percent said the U.S. military should not get involved in such a circumstance, up from 44 percent on August 30.
The poll's findings represent the latest evidence of Americans' reluctance to get involved in another military action after more than a decade of war in Iraq and Afghanistan.
Ipsos pollster Julia Clark said the poll suggests that "the American public has very little appetite for intervention of any kind, anywhere."
The poll's release came as the Obama administration continued to press its case for military action in Syria - and as a potential diplomatic solution appeared to emerge in a crisis that has vexed the White House.
The president planned to sit for six network television interviews on Monday as he stepped up an intense - but decidedly uphill - fight for a skeptical Congress' authorization of military force. Obama also planned to give a nationally televised speech to Americans on Tuesday night.
Meanwhile, an offer from Russia to help put Syria's stock of chemical weapons under international control raised the prospect of an agreement that could help Obama avoid an unpopular military action - and perhaps save him from an embarrassing rejection by Congress.
Even if Obama were to give a very well-received speech on Tuesday about the need for military action, Clark said, "there is never going to be a majority shift for intervention. ... The margin (opposing involvement in Syria) is just too large."
She added that as Americans learn more about the ongoing conflict in Syria and Assad's alleged use of chemical weapons, "they become increasingly opposed" to U.S. intervention.
Clark said Americans' taste for intervention in Syria also likely has been dampened by the ongoing political debate in Washington sparked by Obama's call for congressional authorization and the generally negative view Americans have of politicians.
"When we do policy polling on any issue, when you begin to introduce the politicians and legislators - everybody becomes more negative," she said.
The Reuters/Ipsos poll surveyed 1,450 Americans. Its credibility interval, similar to a margin of error, was 2.9 percentage points for each answer.
(Reporting by Mark Felsenthal; Editing by David Lindsey and Eric Beech)