As the U.S. and other Western nations sharply denounced the Assad and Putin regimes for the deadly gas attack in Syria, Russia on Wednesday tried to deflect blame by pointing to Syrian rebels.

"It's necessary to demand that the rebels offer full access to study the area and collect necessary information," Russian Foreign Ministry spokeswoman Maria Zakharova said during an emergency meeting of the United Nations Security Council.

HALEY SLAMS RUSSIA OVER SYRIAN CHEMICAL ATTACK, WARNS UNITED STATES MAY TAKE 'OUR OWN ACTION'

Russia, which happens to be Syria's most powerful ally, insisted the chemicals that killed at least 75 people were spread when Syrian warplanes bombed a facility where rebels were building chemical weapons. Top Syrian rebels leaders have denied they were responsible for the attack.

Russia also insisted the investigation use "reliable facts" instead of becoming a "long-distance" study of what unfolded.

EXCLUSIVE: WITNESSES DESCRIBE HORRORS OF ATTACK

The Security Council was weighing a resolution condemning chemical weapons use in Syria. Russia, which has veto power, has indicated it opposes the resolution. Syrian officials also denied they were behind the massacre.

U.S. Ambassador to the U.N. Nikki Haley did not hold back, calling the attack "a new low, even for the barbaric Assad regime." She added, "How many more children have to die before Russia cares?"

Near the end of her speech, she remarked: "When the United Nations consistently fails in its duty to act collectively, there are times in the life of states that we are compelled to take our own action."

Britain's U.N. ambassador Matthew Rycroft said his country had seen nothing that suggested any opposition groups "have the sort of chemical weapons that would be consistent with the symptoms that we saw yesterday."

He pointed out that only one air force -- Assad's -- has used such weapons in the six-year civil war. "We have every indication that this was a sustained attack using aircraft over a number of hours."

Fox News' Cody Derespina and The Associated Press contributed to this report.