NEW YORK, Sept. 21 (UPI) -- U.S. Secretary of State John F. Kerry didn't pull his punches against the Russian government at the United Nations on Wednesday -- blasting Moscow for this week's attack on a convoy carrying relief supplies into war-battered Syria.
Speaking to the U.N.'s Security Council, Kerry berated Russia for the convoy strike, which witnesses and some experts believe was carried out by Syrian President Bashar Assad's regime and advocated, by proxy, in Moscow.
The Russian and Syrian governments called off a week-old cease-fire on Monday, citing violations by opposition forces. Immediately thereafter, Assad's forces resumed military force against rebels.
Kerry slammed Russia and Syria for allegedly attacking the humanitarian procession, as well as remarks from Moscow's defense ministry on Tuesday that denied responsibility.
"How can people go sit at a table with a regime that bombs hospitals and drops chlorine gas again and again and again and again and again and acts with impunity," Kerry asked. "You're supposed to sit there and have happy talk in Geneva while the regime drops bombs?"
More than a dozen people in the aid convoy, which attempted to deliver much-needed supplies to Aleppo, were killed in the strike early Monday.
Russia's defense ministry said a day later that neither Moscow nor Syria attacked the convoy, and even questioned whether the convoy was attacked at all.
Defense Ministry spokesman Igor Konashenkov told reporters that a preliminary assessment indicated the convoy caught fire rather than being hit by mortar shells.
"The trucks and the food and the medicine just spontaneously combusted," Kerry said incredulously, calling the attack a "flagrant" violation of international law. "Anybody here believe that?"
Kerry claims Moscow has backtracked on taking responsibility for the attack and said simple logic indicates the Russians are lying. He also expanded his denouncement of Russia and Syria to include an airstrike on a hospital facility near Aleppo on Tuesday night that killed four aid workers.
"There are only two countries that have planes that are flying during the night or flying in that particular area at all," the State Department chief said in his speech. "Russia and Syria.
"Twenty aid workers were killed in an outrageous, sustained, two-hour attack directed at a fully authorized humanitarian mission near Aleppo -- fully authorized. All of the permits had been given. Everybody was on notice."
"It raises a profound doubt about whether Russia and the Assad regime can or will live up to the obligations that they agreed to in Geneva," Kerry added.
The Obama administration leader's remarks came as the United Nations announced Wednesday that it will resume aid deliveries in Syria -- including the battle-torn city of Aleppo.
"While our hearts go out to [Monday's] victims and their loved ones, United Nations humanitarian agencies are needed now more than ever, and will stay and deliver for the people of Syria," the United Nations Office for the Coordination of Humanitarian Affairs said in a statement.
Before wrapping his speech Wednesday, Kerry called on the international community to take a stand against Russia, Syria and any other nation that is helping to "sabotage" the delicate peace process.
"This is not a joke. We're in serious business here," he said, calling the Syrian conflict "the greatest humanitarian catastrophe since World War II."