Barack Obama

St. Petersburg, Russia — President Barack Obama on Wednesday declared the world’s credibility “is on the line” when it comes to punishing Syrian President Bashar Assad for his regime’s purported use of chemical weapons.

Speaking at a press conference in Stockholm, Sweden, ahead of a global economic summit in Russia where he will seek to rally support for a U.S. military strike against Syria, Obama said the “red line” he set against a year ago against Syria’s use of chemical weapons isn’t his, but an international standard.

“I didn’t set a red line, the world set a red line,” Obama said. “My credibility’s not on the line. The international community’s credibility is on the line. And America and Congress’s credibility’s on the line.”

Yet the difficulty Obama faces in achieving a global consensus was illustrated at the press conference with Swedish Prime Minister Fredrik Reinfeldt , who decried the use of chemical weapons and said he understood Obama’s predicament, but said Sweden wants United Nations involvement and a political resolution to the carnage in Syria.

“I understand the problem of not having a reaction to abuse of chemical weapons and what kind of signal that sends to the world,” Reinfeldt said, adding, “But this small country will always say ‘Let’s put our hope into the United Nations, let us push on some more to get a better situation.’ ”

Obama staunchly defended his push for a strike, evoking the death of children from exposure to chemical weapons.

“The moral thing to do is not to stand by and do nothing,” Obama said. “I do have to ask people if in fact you’re outraged by the slaughter of innocent people, what are you doing about it?”

Though Obama has chosen to act before a UN investigation is completed, he said U.S. intelligence shows there’s no doubt that chemical weapons were used by the regime.

“Keep in mind I’m somebody who opposed the war in Iraq, and I’m not interested in repeating mistakes about basing decisions on faulty intelligence,” Obama said.

The press conference came hours after Russian President Vladimir Putin in an interview with the Associated Press warned the U.S. against military strikes in Syria, saying without the sanction of the United Nations any assault would be “inadmissible and can only be interpreted as an aggression.”

Putin said the Russian government has provided some components of the S-300 air defense missile system to Syria but has suspended shipments “for now.” He suggested that Russia may sell the potent missile systems elsewhere if Western nations attack Syria without U.N. Security Council backing.

Russia has routinely vetoed sanctions against Syria in the United Nations, but Putin didn’t rule out supporting a UN resolution to support military strikes if it’s proven that the Syrian regime used chemical weapons.

He made clear his threshold for such support is high, calling it “absolutely absurd” that the government would use chemical weapons at a time when it was closing in on the rebels.

In the interview, Putin insisted he and Obama could have constructive talks — even though he said he was disappointed Obama cancelled a meeting with him in Moscow.

A White House official said that although there was no plan for a formal meeting with Putin at the summit in St. Petersburg, the White House “would expect the two presidents to have an opportunity to speak on the margins of the various meetings of the G-20.”

Obama will hold formal bilateral meetings with President Xi of China, Prime Minister Abe of Japan and President Francois Hollande of France.

Putin downplayed his frosty relationship Obama, which Russia analysts have said is among the worst in US-Russian and US-Soviet leader relationships.

“President Obama hasn’t been elected by the American people in order to be pleasant to Russia,” Putin told the AP. “And your humble servant hasn’t been elected by the people of Russia to be pleasant to someone either.”

“We work, we argue about some issues. We are human. Sometimes one of us gets vexed. But I would like to repeat once again that global mutual interests form a good basis for finding a joint solution to our problems,” Putin said.

In a sign the U.S. surveillance program continues to be a source of concern even among U.S. allies, the first question Obama got from a Swedish reporter at the press conference was about the NSA program.

He insisted the U.S. is not “snooping at people’s emails and or listening to their phone calls.”

The program’s focus, he said, is on counterterrorism and cyber security.