Correction: A previous headline on this article misidentified the conference as the G-8 Summit. It is the Group of 20 summit. This headline has been updated.

A police boat patrols the waters near the Stockholm Royal Palace, background right, in Stockholm on Tuesday, ahead of the scheduled visit by President Obama on Wednesday and Thursday. (ANDERS WIKLUND/ap)

As his administration tries to rally support in Congress for military strikes in Syria, President Obama will begin a high-stakes trip to Sweden and Russia on Wednesday that could show whether the United States has broad international backing for action.

At the Group of 20 summit in St. Petersburg, the strife in Syria and uncertainty about Obama’s plans are likely to overshadow an agenda focused on economic issues. Privately, Obama will try to persuade world leaders to support U.S.-led action in Syria — putting him at odds with the summit’s host, Russian President Vladi­mir Putin, a key ally of the Syrian regime who will press his case against strikes.

Obama’s visit comes as the U.S.-Russia relationship deteriorates over disagreements about Syria, Russia’s new law targeting “homosexual propaganda” and the country’s protection of Edward Snowden, a former National Security Agency contractor who leaked highly classified documents about U.S. surveillance programs.

Obama had planned to meet privately with Putin in Moscow ahead of the G-20 summit but called off the meeting after Russia granted asylum to Snowden. No bilateral meeting between the two leaders has been announced for the visit, although a U.S. official said they will “have many opportunities to engage.”

Anders Aslund, a Russia specialist at the Peterson Institute for International Economics, said there are major risks for Obama in attending the summit.

“I think that this will be really a trap that President Obama is getting into for no good reason,” Aslund said. “When there is an event like this, the Russians are in charge. The host is always in charge, and there’s nothing that President Obama can accomplish in St. Petersburg. He has no support for Syria there. He will only get beaten up over it.”

Obama is planning to meet with French President Francois Hollande and Chinese President Xi Jinping, U.S. officials said. Experts said it will be difficult for him to gain support on Syria as long as the scope of possible strikes or whether Congress will authorize them remains uncertain.

“He’s going over there, he wants their support on Syria, but for them it’s like, ‘Until your Congress says, ‘yes,’ ” said Mark Katz, a Russia analyst at George Mason University. “For risk-averse politicians, why go out on a limb? They don’t want to state their support for the use of force against Syria and then have Obama not do it.”

British Prime Minister David Cameron supports action against the Syrian regime, but his Parliament last week voted down any military action. In France, Hollande has signaled support as well, although his country’s Parliament is still debating the issue.

Putin has given Syrian President Bashar al-Assad’s government critical military and economic support throughout the country’s bloody civil war. He has spoken out against a U.S.-led strike in retaliation for the Assad regime’s alleged use of chemical weapons to kill hundreds of civilians.

Russian officials said Putin expects to take advantage of the G-20 summit to discuss Syria with other world leaders — among them, Xi, who on Tuesday was touring the former Soviet republics of Central Asia and plans a bilateral meeting in St. Petersburg with Putin.

“One should perhaps not miss an opportunity to tell something to each other,” Sergei Vershinin, director of the Russian Foreign Ministry’s Middle East and North Africa department, said Tuesday, referring to Syria. The issue, he said, comes down to “preventing the military development of the situation that will only further aggravate the situation.”

Obama will begin his overseas trip Wednesday in Stockholm, where he intends to highlight trade alliances, global development and climate change. He is scheduled to meet with Prime Minister Fredrik Reinfeldt and King Carl XVI Gustaf and eat dinner with leaders from Denmark, Finland, Iceland and Norway.

Obama will tour the Royal Institute of Technology, a cutting-edge research facility, and visit the Great Synagogue and Holocaust memorial, where he will pay tribute to humanitarian Raoul Wallenberg. The late Wallenberg, a Swede, was credited with helping save tens of thousands of Jews in Nazi-occupied Hungary. He vanished after being detained by Soviet authorities in 1945, and the cause and timing of his death remain uncertain.

Obama will arrive in St. Petersburg on Thursday. The summit comes at a tense moment for human rights in Russia because of a new law that criminalizes the promotion of homosexual behavior if children might be exposed. Obama has spoken out against the measure.

Several human rights activists in Russia said Obama has invited them to meet with him on Thursday. “Russia’s leadership needs to hear from its G-20 partners that its crackdown does not serve but instead contradicts the interests of an open society,” said Tanya Lokshina, Russia program director at Human Rights Watch.

Englund reported from Moscow.