The U.N. humanitarian chief briefly visited the battered Homs neighborhood of Baba Amr with a Syrian Red Crescent team on Wednesday, as Washington revealed it is mulling non-lethal aid to the rebels.

Valerie Amos was stopped from going into areas of Homs still held by the opposition, despite receiving assurances from Syrian Foreign Minister Walid Muallem in earlier talks that she could go to any part of the country, her spokeswoman Amanda Pitt told Agence France Presse.

Syria's armed opposition groups cannot defeat President Bashar al-Assad's forces, a think-tank expert said Wednesday.

Toby Dodge, the senior Middle East expert at the International Institute for Strategic Studies (IISS), said the fractured nature of the opposition forces meant they were more of an "irritant" to the regime than a threat.

Foreign Minister Adnan Mansour on Wednesday voiced rejection of a call by U.S. Ambassador to Lebanon Maura Connelly for the Lebanese authorities to provide protection for the members of the rebel Free Syrian Army who flee to Lebanon, as President Michel Suleiman called the Higher Defense Council to convene on Thursday to discuss the latest developments related to the Lebanese-Syrian border.

“Lebanon cannot heed such a request; it rather acts according to its interest, security situation and capabilities, and we cannot provide support to armed elements stationed in the Lebanese territory,” Mansour said in an interview on Al-Manar television.

Foreign Sunni jihadists are fighting alongside Syrian rebels who have taken on President Bashar al-Assad, but their numbers are hard to assess and almost certainly small, insurgents and analysts say.

An Agence France Presse correspondent who met several Syrian rebels over a week in the city of Homs, which was recaptured by regime forces on Thursday, said he sometimes saw them mingling with strangers of the same beliefs.

Former Prime Minister Fouad Saniora noted on Wednesday that some sides in Lebanon who are accusing others of meddling in the Syrian crisis are in fact guilty of these charges.

He said: “Those calling for the freedom in Lebanon cannot do so while simultaneously supporting the Syrian regime.”

The United Nations' humanitarian chief Valerie Amos entered the battered Baba Amr rebel district of Homs in central Syria on Wednesday along with a Syrian Red Crescent team, the ICRC said.

"Madame Amos entered with the team of volunteers from the Syrian Red Crescent, which stayed 45 minutes in the district," said a spokesman from the International Committee of the Red Cross.

Vladimir Putin on Wednesday rejected the idea of Russia offering Syrian President Bashar al-Assad asylum as a way of helping put an end to nearly a year of bloodshed in its Soviet-era ally.

"We are not even discussing this question," news agencies quoted Putin as telling Kremlin reporters.

Former Prime Minister Saad Hariri noted on Wednesday that the Arab Spring allows the Lebanese to “update” their democratic experience and eliminate the remnants of the sectarian wars.

He said: “Democracy protects us all and we must resort to dialogue to face intolerance.”

The U.N. humanitarian chief started a mission to Syria on Wednesday to urge the regime to allow aid into battered protest cities, putting the focus on civilians in a conflict which has cost thousands of lives.

Valerie Amos flew in for a two-day visit, after an international outcry over President Bashar al-Assad's previous refusal to let her in, and is to followed by U.N.-Arab League envoy Kofi Annan on Saturday.

Air France on Wednesday said it had cancelled its Paris-Damascus service "until further notice" because of unrest linked to ongoing protests against Syrian President Bashar Assad's regime.

"Because of the situation in Syria, Air France has decided to suspend its flights to Damascus until further notice," a spokesman said, after the airline had already cancelled two flights to Damascus earlier in the week.