The Obama administration said Wednesday it would take action against the Syrian government even without the backing of allies or the United Nations because diplomatic paralysis must not prevent a response to the alleged chemical weapons attack outside the Syrian capital last week.

New requests for the United Nations to authorize military action in Syria may have complicated the Obama administration’s plan to take retaliatory action on the purported poison gas attack east of Damascus that U.S. officials claim was carried out by President Bashar Assad’s forces.

But a State Department spokeswoman said the U.S. would respond even in the absence of U.N. backing.

“We cannot be held up in responding by Russia’s intransigence — continued intransigence — at the United Nations,” Marie Harf said. “The situation is so serious that it demands a response.”

The U.S. has not publicly presented proof that Assad’s government used deadly chemical weapons near Damascus last week. Even so, U.S. officials, including Vice President Joe Biden, have pointed a finger squarely at Assad. The administration was planning a teleconference briefing Thursday on Syria for leaders of the House and Senate and national security committees in both parties, U.S. officials and congressional aides said.

U.S. intelligence intercepted lower-level Syrian military commanders’ communications discussing the chemical attack, but the communications don’t specifically link the attack to an official senior enough to tie the killings to Assad himself, according to three U.S. intelligence officials. They spoke on condition of anonymity because they were not authorized to discuss the intelligence publicly.

The White House ideally wants intelligence that links the attack directly to Assad or someone in his inner circle, to rule out the possibility that a rogue element of the military decided to use chemical weapons without Assad’s authorization.

That quest for added intelligence to bolster the White House’s case for a strike against Assad’s military infrastructure has delayed the release of the report by the Office of the Director for National Intelligence laying out evidence against Assad. The report was promised earlier this week by administration officials.

The CIA and the Pentagon have been working to gather more human intelligence tying Assad to the attack, relying on the intelligence services of Jordan, Saudi Arabia and Israel, the officials said.

Both the CIA and the Defense Intelligence Agency have their own human sources — the rebel commanders and others who cross the border to brief CIA and defense intelligence officers at training camps in Jordan and Turkey. But their operation is much smaller than some of the other intelligence services, and it takes longer for their contacts to make their way overland.

Britain added a hurdle to deliberations about a military strike on Wednesday when it went to the U.N. Security Council with a draft resolution that would authorize the use of military force against Syria. This, as momentum seemed to be building among Western allies for a strike against Syria.

The draft seemed doomed before it was proposed. As expected, the five permanent members of the security council failed to reach an agreement as Russia reiterated its objections to international intervention in the Syrian crisis. Russia, along with China, has blocked past attempts to sanction the Assad government.

Russian Foreign Minister Sergey Lavrov has said that the use of force without a sanction of the U.N. Security Council would be a “crude violation” of international law and “lead to the long-term destabilization of the situation in the country and the region.”

Syria, which sits on one of the world’s largest stockpiles of chemical weapons, has denied the charges. Moreover, Syria’s U.N. ambassador, Bashar Ja’afari, is demanding that United Nations experts investigate three alleged chemical weapons attacks against Syrian soldiers. He said the attacks occurred on Aug. 22, 24 and 25 in three suburbs of the Syrian capital and dozens of soldiers are being treated for inhaling nerve gas.

The draft U.N. resolution was an effort to bolster British Prime Minister David Cameron’s case that a military action is needed. Cameron has called an emergency meeting of the British Parliament on Thursday to vote on whether to endorse international action against Syria.

He’s promised British lawmakers he would not go to war until chemical weapons inspectors had a chance to report back to the world body about their findings. That means British involvement in any potential strike wouldn’t occur until next week at the earliest.

But British Foreign Secretary William Hague suggested that U.S. military action need not be constrained by Britain’s parliamentary timetable.

“The United States are able to make their own decisions,” he told reporters late Wednesday, just after speaking with Secretary of State John Kerry. “Of course, we will remain closely coordinated with them and in close touch with them,as we are every day.”

Certain members of Congress are expected to get a classified U.S. intelligence report laying out the case against Assad. An unclassified version is to be made public. Officials say it won’t have any detail that would jeopardize sources and methods.

Administration officials have asserted that the use and potential spread of chemical weapons are a threat to U.S. national security.

“The mass-scale use of chemical weapons, or of course the potential proliferation of those weapons, flagrantly violates an important international norm and threatens American national security,” Harf said.

Some lawmakers have argued that Congress must authorize any military action unless there has been an attack on the U.S. or the existence of an eminent threat to the U.S. Both Democrats and Republicans on Wednesday pressed the White House to provide a clear explanation of how military action would secure U.S. objectives.

Specifically, in a letter to Obama, House Speaker John Boehner asked him to make his case to Congress and the public about how military action would “secure American national security interests, preserve America’s credibility, deter the future use of chemical weapons, and, critically, be a part of our broader policy and strategy.”

Boehner said it was “essential you address on what basis any use of force would be legally justified.”

(AP)