The White House has explicitly blamed Russia for this week's deadly attack on a humanitarian aid convoy in Syria, an attack that prompted angry denunciations and put a week-old cease-fire on the brink of collapse.
The comments by deputy national security adviser Ben Rhodes on September 20 were the bluntest accusations leveled by Washington to date on the incident near Aleppo.
"There only could have been two entities responsible -- either the Syrian regime or the Russian government," Rhodes was quoted by news agencies as saying. "In any event, we hold the Russian government responsible for air strikes in this space."
The September 19 strike on aid trucks and a warehouse killed at least 20 civilians. It prompted the United Nations to suspend all humanitarian convoys in Syria.
It also unusually sparked angry remarks from UN chief Ban Ki-moon, who called those behind the attack "cowards.”
In his address to the UN General Assembly on September 20, Ban said those "delivering life-saving aid were heroes" and called the attack "sickening, savage, and apparently deliberate."
The Syrian Arab Red Crescent said it was also suspending all work in Aleppo Province for three days in protest.
It wasn’t immediately clear whose aircraft were behind the strikes, but unnamed U.S. officials told AFP and Reuters that two Russian Su-24 jets were in the skies above the convoy at the exact time of the attack. That has led U.S. intelligence to conclude Russia was to blame.
The Russian Defense Ministry rejected reports that its warplanes were involved, saying instead that the convoy had caught fire and hinting that Moscow believes either militants with the Al-Nusra Front or members of the White Helmets, a Syrian civil defense group, were to blame.
“[The question of] who caused it and with what aim can be answered only by…representatives of the White Helmets organization, which is close to the Al-Nusra Front,” Russian news agencies quoted Defense Ministry spokesman, Major General Igor Konashenkov, as saying.
Russian and Syrian air forces “did not conduct any strikes” against the aid convoy, Konashenkov said.
The Syrian military also denied bombing the convoy, state media reported.
The attack severely damaged hopes that a week-old cease-fire brokered by Russia and the United States could hold, despite declarations by Washington, Moscow, and more than a dozen other countries on September 20 that the deal remained alive despite the mounting violence.
"The cease-fire is not dead," U.S. Secretary of State John Kerry said. "We are going to continue to work. We are going to meet again Friday on some specific steps."
Kerry and Russian Foreign Minister Sergei Lavrov led the meeting of the 23-nation International Syria Support Group on the sidelines of the UN General Assembly.
British Foreign Secretary Boris Johnson told reporters that "the mood is that nobody wants to give this thing up."
"Quite frankly the Kerry-Lavrov process is the only show in town and we've got to get that show back on the road," Johnson added.
"Is there hope? I can't answer that yet, but we should do everything we can," asked French Foreign Minister Jean-Marc Ayrault.
Addressing the General Assembly for the final time on September 20, U.S. President Barack Obama reiterated Washington’s position that there can be no military solution to the 5-year-old Syria conflict.
"There's no ultimate military victory to be won. We're going to have to pursue the hard work of the diplomacy that aims to stop the violence and deliver aid to those in need," Obama said.