ST. PETERSBURG, Russia — Beset by divisions at home and abroad, President Barack Obama candidly acknowledged deep challenges Friday in winning support for a military strike against Syria from international allies and Congress.
He refused to say whether he might act on his own, a step that would have major implications for the United States, as well as for the remainder of his presidency.
The White House laid out an intense week of lobbying. Obama will address the nation Tuesday night from the White House.
"I did not put this before Congress just as a political ploy or as symbolism," Obama said, adding that it would be a mistake to talk about any backup strategy before lawmakers vote on a use-of-force resolution.
The president spoke to reporters at the end of a two-day international summit, where he sought backing for a strike against Syria in retaliation for a deadly chemical weapons attack against civilians. But Obama appeared to leave the summit with no more backing than he had when he arrived.
In fact, Russian President Vladimir Putin, a staunch ally of Syrian President Bashar Assad, said he was the one with support from the majority of countries attending the Group of 20 meeting. Putin insisted anew that Obama seek approval from the United Nations before taking military action, despite the fact that Russia has blocked previous Security Council efforts to punish Assad throughout Syria's bloody 2½-year civil war.
The White House tried to counter Putin's assessment by releasing a joint statement from the United States and 10 other countries announcing support for "efforts undertaken by the United States" to enforce an international prohibition on chemical weapons use. The statement did not specify military action against Syria, but administration officials said the intent was to show international support for that type of response.
The countries signing the statement with the United States were Australia, Canada, France, Italy, Japan, South Korea, Saudi Arabia, Spain, Turkey and the United Kingdom.
Putin said the U.S. push for military action has been supported only by Turkey, Canada, Saudi Arabia and France.
"The use of force against a sovereign nation is only possible as self-defense — and Syria hasn't attacked the United States — and on approval of the U.N. Security Council," Putin said. "Those who do otherwise place themselves outside the law."
Indeed, Obama's coalition appeared anything but strong. Britain's Parliament has already voted against military action. Even French President Francois Hollande, who has expressed willingness to form a military coalition with the United States against Syria, displayed sudden caution, saying he would wait until a United Nations investigation into the Aug. 21 sarin gas attack was released before deciding whether to intervene militarily. The U.N. report is not expected to be released until mid to late September.
In addition to Obama's Tuesday night speech, administration officials have scheduled new classified briefings for lawmakers, and White House chief of staff Denis McDonough was planning to make the rounds on all five Sunday talk shows.
The president admitted his campaign may not succeed.
"It's conceivable at the end of the day I don't persuade a majority of the American people that it's the right thing to do," he said. "And then each member of Congress is going to have to decide."
The options facing the United States and the international community are neither convenient nor appetizing, Obama said. But he appealed for action on moral grounds, citing U.S. estimates that the chemical weapons attack killed more than 1,400 people, including 426 children. Other estimates are somewhat lower.
"There are times where we have to make hard choices if we're going to stand up for the things that we care about," he said. "And I believe that this is one of those times."
Two recent polls show Americans oppose airstrikes, with a Pew Research Center survey showing 48 percent opposed and 29 percent in favor and a Washington Post-ABC News poll showing 59 percent opposed and 36 in support. Both surveys were taken over the Labor Day holiday weekend as the United States released its assessment of whether the Syrian government used chemical weapons and Obama announced he would seek congressional approval.
Sen. Dianne Feinstein, D-Calif., chairwoman of the Senate Intelligence Committee, said the public sentiment might be different if Americans could see the evidence from the chemical weapons attack, including the convulsions and other side effects of the nerve gases.
An Associated Press survey found 34 senators in support or leaning in favor of authorizing military action, 32 against or leaning that way and 34 undecided. Tallies in the House show a significant number of Republicans and Democrats are also opposed to military action or leaning against it.