BEIRUT -- The Latest on developments in Syria, where a cease-fire is faltering further after airstrikes hit an aid convoy overnight (all times local):
The White House says the U.S. holds Russia responsible for airstrikes by either Syria or Russia that hit an aid convoy in Syria.
White House Deputy National Security Adviser Ben Rhodes said all information indicates an airstrike hit the convoy. He says that since the Syrian rebels lack an air force, that means either Syria or Russia conducted the strikes.
He says regardless of who carried out the strike, the U.S. considers Russia responsible because it was Russia's responsibility under the cease-fire deal to limit Syrian airstrikes.
Russia and Syria both denied carrying out the convoy bombing. Russia's Defense Ministry has blamed the damage on a cargo fire.
Syria's Foreign Ministry has condemned an address by the U.N. Secretary General that accused the Syrian government of killing more civilians in the Syrian war than any other side.
In a statement Tuesday, the Foreign Ministry says the U.N., under the era of outgoing Secretary-General Bank Ki-moon, "has deviated from its role in finding just solutions for international problems."
It says the Syrian people possess the right to self-determination and "do not need Ban's advice."
The Ministry says the address had deviated "extremely far from the rules of the UN charter," and added that the international body had failed to resolve any conflicts during Ban's era.
Moscow is angrily denying that the Russian or Syrian air force were involved in an overnight attack on a humanitarian convoy.
The Russian Foreign Ministry on Tuesday said that "we responsibly say that neither the Russian nor the Syrian air force conducted any strikes on the U.N. aid convoy on the southwestern outskirts of Aleppo."
It describes claims that Russian or Syrian aircraft were involved as "hasty and unfounded," adding the allegations could be aimed at distracting attention from an earlier strike on Syrian army positions by the U.S.-led coalition.
Syrian activists and paramedics have said the airstrikes on the convoy were conducted by Russian or Syrian aircraft.
The attack Monday night killed 20 civilians and prompted the U.N. to suspend all aid convoys in Syria.
U.N. Secretary-General Ban Ki-moon is denouncing the "sickening, savage and apparently deliberate attack" on a U.N.-Syrian Arab Red Crescent convoy in Syria, calling the bombers "cowards."
The U.N. chief told world leaders at Tuesday's opening of the U.N. General Assembly's ministerial meeting that "just when we think it cannot get any worse, the bar of depravity sinks lower."
The Red Crescent said about 20 civilians were killed. Ban called those delivering aid "heroes."
He says the United Nations was forced to suspend aid convoys "because of this outrage"
Ban blames the Syrian government for most deaths and says it "continues to barrel bomb neighborhoods and systematically torture thousands of detainees."
He says countries "that keep feeding the war machine also have blood on their hands" and accuses unnamed governments attending the U.N. meeting of ignoring, facilitating, funding, planning and carrying out "atrocities" against civilians on all sides.
The U.S. is imposing sanctions on a Syrian-based radical group formerly affiliated with al-Qaida.
The State Department says Tuesday in a statement that Jund al-Aqsa had once been part of the group formerly known as the Nusra Front, a splinter group of al-Qaida that later cut its ties with the extremist organization. Jund al-Aqsa primarily operates in the northern Syrian cities of Idlib and Hama.
The State Department says that Jund al-Aqsa has been determined to "have committed, or pose a significant risk of committing, acts of terrorism that threaten the security of U.S. nationals or the national security, foreign policy or economy of the United States."
The international medical charity Doctors Without Borders says it is "shocked' by the attack on an aid convoy in Syria, calling it the latest example of the "continuous disregard paid to the basic rules of war" in the six-year conflict.
The group, known by its French acronym MSF, has called Tuesday on international powers involved in the conflict to take "more concrete steps" to end attacks on civilian infrastructure.
MSF-supported clinics and medical facilities have frequently come under attack in Syria, as part of what the rights group Physicians for Human Rights describes as "the most widespread and systematic assault on health care in the world to date."
In July alone, 44 attacks on health facilities were reported, mostly in rebel-held areas.
The brother of an aid worker who was killed when an aid convoy was attacked in Syria said the Red Crescent staffer was overseeing the unloading of trucks when a bomb hit the warehouse, killing him inside his car.
Ali Barakat, who also works for the Red Crescent, says Tuesday he threw himself on the floor when the first missile hit and killed his brother, Omar Barakat.
Ali Barakat says more than 20 missiles hit the area Monday night. The International Committee of the Red Cross says 20 civilians were killed in the aid convoy attack.
The President of the Syrian Red Crescent, Abdulrahman Attar, called father-of-nine Omar Barakat "a committed and brave member" of the group. The Red Crescent has lost 54 staff and volunteers in the past six years of conflict.
A rescue worker who witnessed the strikes on a Red Crescent warehouse and trucks carrying U.N. aid in Syria says more than 20 missiles pounded the area for hours, even hitting his team as they searched the debris for survivors.
Hussein Badawi, who leads the Syrian Civil Defense - also known as the White Helmets - in Uram al-Kubra, says Tuesday the strikes came from helicopters and land missiles.
He accuses Syrian and Russian aircraft of taking part in an attack that lasted more than two hours, covering a 100 yard-radius. Badawi's team arrived on the scene after the first land missiles hit.
Another witness, Mohammed Rasoul, says the convoy was "erased from the face of the earth."
Badawi says the rescue effort was hampered by the dark and 11 strikes that came while the rescue team was searching for survivors.
Russia's Defense Ministry spokesman says the deadly attack on an aid convoy in Syria the previous night does not appear to have been from an airstrike.
Igor Konashenkov says that the Russian military has "carefully studied the video recordings of the so-called activists from the scene and found no signs that any munitions hit the convoy."
Konashenkov remarks on Tuesday were reported by the state news agency Tass. He denied that Russian warplanes or those of the Syrian government had conducted any airstrikes on the aid convoy.
He says that "everything shown on the video is the direct consequence of the cargo catching fire, and this began in a strange way simultaneously with militants carrying out a massive offensive in Aleppo."
Syria's military is also denying it was behind airstrikes that hit an aid convoy in northern Syria, killing more than a dozen people the night before.
Earlier, the Russian military denied it was behind the strikes.
Syrian state TV quoted an unnamed military official as saying that reports about the Syrian army targeting an aide convoy are not true. Tuesday's report came after an aid convoy was hit in the northern province of Aleppo.
The airstrikes hit a truck convoy on Monday night, killing around 20 people, including a local Syrian Red Crescent volunteer.
Russia's Defense Ministry is denying that Russian warplanes or those of the Syrian government conducted the deadly airstrikes that targeted an aid convoy in northern Syria the previous night.
Defense Ministry spokesman Igor Konashenkov says that "no kind of air attack on a humanitarian convoy of the United Nations in the southwest outskirts of Aleppo was conducted by Russian or Syrian aviation."
His remarks were carried on Tuesday by the state news agency Tass.
The airstrikes on Monday night hit a truck convoy, killing around 20 people, including a local Syrian Red Crescent volunteer.
The International Committee of the Red Cross says around 20 civilians were killed in the airstrikes that hit an aid convoy in northern Syria the previous night.
ICRC said in its statement on Tuesday that the dead include a member of the Syrian Red Crescent.
ICRC president Peter Maurer says the attack was a "flagrant violation of international humanitarian law" and "totally unacceptable."
The statement says the civilians were killed as they were unloading trucks carrying vital humanitarian aid and that much of the aid was destroyed, depriving thousands of much-needed food and medical assistance.
Syrian activists and paramedics had said earlier that the airstrikes killed 12 people.
___ 2:15 p.m.
A member of the Syrian Civil Defense - a group of volunteer first responders also known as the White Helmets - has criticized the U.N. humanitarian aid agency for suspending all convoys in Syria.
Ibrahim Alhaj told The Associated Press on Tuesday that Syrian civilians will pay the price for the decision.
The U.N. humanitarian aid agency's decision came after deadly airstrikes on aid trucks the previous night that activists said killed at least 12 people, mostly truck drivers and Red Crescent workers.
Elhaj says the U.N. should have condemned the attacks on the convoy rather than suspending aid.
The U.N. humanitarian aid agency says it has temporarily suspended all convoys in Syria following a deadly airstrike on aid trucks the previous night.
Spokesman Jens Laerke of OCHA says the temporary suspension of the aid deliveries would hold pending a review of the security situation in Syria.
Laerke said on Tuesday that the U.N. aid coordinator had received needed authorizations from the Syrian government in recent days to allow for aid convoys to proceed within Syria.
He said it's "a very, very dark day ... for humanitarians across the world."
The attack late on Monday came just hours after the Syrian military declared the weeklong U.S.-Russian brokered cease-fire had failed. The United States said it was prepared to extend the truce deal and Russia - after blaming rebels for the violations - suggested it could still be salvaged.
Syria's cease-fire has faltered further after an aid convoy was hit by airstrikes, with activists saying at least 12 people were killed in the attack, mostly truck drivers and Red Crescent workers.
It was not clear who was behind the attack, which sent a red fireball into the sky in the dead of night over a rural area in Aleppo province. Both Syrian and Russian aircraft operate over Syria, as well as the U.S.-led coalition that is targeting the Islamic State group.
U.N. officials said the U.N. and Red Crescent convoy was delivering assistance for 78,000 people in the town of Uram al-Kubra, west of the northern city of Aleppo.
Initial estimates indicate that about 18 of the 31 trucks in the convoy were hit, as well as the Red Crescent warehouse in the area.
The Britain-based Syrian Observatory for Human Rights, an activist group that tracks the civil war, said at least 12 were killed in the attack, mostly truck drivers and Red Crescent workers.
White House says US holds Russia responsible for airstrikes that hit UN aid convoy