Russia and China, who twice blocked UN resolutions to condemn ally Syria, were Monday stepping efforts to find a peaceful solution to the crisis, as the Red Cross was again denied access to a battered rebel district.
Russian Foreign Minister Sergei Lavrov said he was preparing for a meeting on Saturday in Cairo with his Arab counterparts to discuss its ally Syria due to the "urgency" of the crisis.
And China said it was sending a new envoy to Damascus and is ready to support international aid under the auspices of the United Nations or another "impartial" organisation.
The diplomatic moves came as the International Committee of the Red Cross said Monday it had still not been granted permission to enter Baba Amr, the rebellious district of Homs overrun four days ago by regime forces.
"Negotiations are still ongoing," ICRC spokesman Saleh Dabbakeh told AFP, amid mounting international outrage against President Bashar al-Assad's regime for its 11-month crackdown on dissent which the UN says has claimed at least 7,500 lives.
And days after Britain and France joined the United States in closing their embassies in Damascus over security fears, Air France cancelled its Monday flight to the Syrian capital, citing the unrest sweeping the country.
Rebel fighters fled Baba Amr on Thursday in the face of a ground assault by regime forces following a month-long shelling blitz which the US-based Human Rights Watch said had killed some 700 people.
The ICRC and the Syrian Arab Red Crescent Society have sought in vain permission to enter Baba Amr, where hundreds of people are reported to have been killed and even more wounded.
On Friday they sent a seven-truck aid convoy to Homs but they were barred from entering Baba Amr, which fleeing residents say is facing an acute humanitarian crisis.
The authorities say the relief agencies are being barred for their own safety due to the presence of bombs and landmines.
But Syrian anti-regime activists say the authorities are keeping the groups out in order to buy time to hide their "crimes."
UN Secretary General Ban Ki-moon has demanded unconditional humanitarian access to Syrian cities, saying there were "grisly" reports of summary executions and torture in Homs, Syria's third largest city in the centre of the country.
The ICRC said it delivered Sunday relief supplies in a nearby village to refugees who had fled Baba Amr.
On the political front Russia and China -- who have faced international criticism for their support of the Syrian regime -- separately announced plans to help find solutions to ease the crisis.
Lavrov said he was preparing for a meeting with Arab foreign ministers on March 10 in Cairo.
"Considering the urgency of the Syria issue, when collective approaches for a settlement need to be found, we view this as a valuable and important format," Lavrov said of the Cairo meeting.
Moscow along with Beijing has twice wielded its Security Council veto to block UN action on the crisis in Syria, first in October last year and again in February.
Lavrov's remarks come a day after Saudi Foreign Minister Prince Saud al-Faisal urged Moscow to "advise" Assad's regime to stop its the "bloodshed and massacres."
In Beijing, foreign ministry spokesman Lu Weimin said that China's former ambassador to Damascus, Li Huaxin, would travel to Syria on Wednesday for meetings with the government and other parties.
"Although the situation is complex and tense, China still thinks that the political resolution of the Syrian issue is the fundamental way to solve the crisis," he said.
On Sunday, Beijing called on both sides to end the violence, even as Syrian forces trained their guns on the rebel city of Rastan, near Homs.
According to Britain-based monitoring group the Syrian Observatory for Human Rights, Syrian artillery fired a barrage of shells into Rastan, which killed seven civilians, four of them children.
Including the Rastan deaths, a total of 19 civilians were killed across Syria on Sunday, the Observatory said. It also reported the death of a soldier in the northwest province of Idlib.
AFP was not immediately able to verify the Observatory's reports because of restrictions on foreign journalists in Syria.
Air France said it was cancelling its Monday Flight AF-570 to Damascus "because of the situation in Syria" and that the return flight on Tuesday was also cancelled.
On Friday, France said it was closing its embassy in Syria, two days after Britain did the same.
The United States closed its embassy in the Syrian capital on February 6 and the Polish embassy now provides limited consular services to US citizens in the country.