UN Secretary-General Ban Ki-moon has called on Damascus to grant immediate access for aid workers to Syria.
Ban made the call after the International Committee of the Red Cross (ICRC) announced it had been refused permission to deliver aid to an embattled district of the Syrian city of Homs.
In a statement, ICRC President Jakob Kellenberger said the decision by Syrian authorities to deny aid groups access to Baba Amr district was "unacceptable."
The statement said Damascus had given the Geneva-based agency a "green light" on March 1 to enter the next day.
Kellenberger said the seven-truck aid convoy carrying food, medicine, and blankets, along with ambulances from the Syrian Red Crescent, would stay in Homs overnight in hopes of entering Baba Amr "in the very near future."
The delay comes amid allegations by Syria's opposition that government forces were conducting summary killings.
Speaking to journalists in New York on March 2, Ban urged the Syrian authorities to open Baba Amr "without any preconditions to humanitarian communities."
"The images which we have seen in Syria [are] atrocious. It is totally unacceptable, intolerable," Ban said.
"How, as a human being, can you bear with this situation? This really troubles me. I'm deeply sad seeing all what's happening."
In Washington, White House spokesman Jay Carney condemned the "brutality" of President Bashar al-Assad's regime, saying, "The brutalities they carried out in the last 24 to 48 hours is disgraceful."
Security forces took Baba Amr district from rebels on March 1 after it suffered bombardment by government forces in recent weeks.
Edith Bouvier and William Daniels, two French journalists caught up in the shelling and smuggled out of Homs into Lebanon, were flown back to France. Bouvier was injured in the bombardment of a makeshift media center last week.
The ICRC said it had received the bodies of two other journalists killed in the bombardment, Marie Colvin of Britain's "Sunday Times" and French photojournalist Remi Ochlik, and will take them to Damascus.
France Closes Embassy, Russia Blames West
France, meanwhile, has announced it is closing its embassy in Damascus to protest what President Nicolas Sarkozy called the "scandalous" repression by the Syrian regime.
The leaders of the 27 European Union member states, meeting in Brussels on March 2, said they were "horrified" by the atrocities that reports say are taking place in Syria. The bloc said it will work closely with those working to record "these appalling crimes" so that those responsible are held accountable.
Russia's Prime Minister Vladimir Putin, however, has accused the West of fueling the Syrian conflict by backing the opposition.
Speaking to a meeting of foreign newspaper editors in Moscow, Putin asked, "Do they want Assad to pull out his forces so the opposition moves right in?"
"Is that a balanced approach?" he asked.
"We are trying to be guided not by what you show or write but by what is taking place in reality. And what is taking place in reality? An armed civil conflict," Putin said. "Our goal is not to aid any particular side, the government or the armed opposition, but to achieve an all-Syrian reconciliation."
Putin called for both Syrian government and opposition forces to pull out of besieged cities to end the bloodshed.
Putin denied that Russia has any "special relationship" with the Syrian regime and also defended the February veto by Russia and China of a United Nations Security Council resolution on the Syria.
Russia is a leading supplier of arms to the Syrian government and operates a naval base at the port of Tartus on Syria's Mediterranean coast.
At the United Nations, the Security Council -- including Russia and China -- has expressed "deep disappointment" at Syria's failure to allow UN humanitarian aid chief Valerie Amos to visit the country and urged that she be allowed to visit the country.
French President Sarkozy has said two journalists who were trapped in Syria are now safely in Lebanon. Edith Bouvier and William Daniels had been struck in the Baba Amr during the monthlong siege. Bouvier was wounded last week when government forces targeted a makeshift press center in Baba Amr. Two Western journalists died in that assault.
The UN Security Council estimates that more than 7,500 people -- including around 500 children -- have been killed in the 11-month-old crackdown that has followed an outbreak of Arab Spring-style protests and insurrection.
With AP, AFP, and Reuters reporting