Lebanese Forces leader Samir Geagea received a phone call from Syrian Opposition leader George Sabra on Wednesday, during which both men discussed the involvement of Hizbullah fighters in Syria's conflict.

They also tackled how this issue might be reflected on the people of both countries.

U.S. Defense Secretary Chuck Hagel urged caution Wednesday over an Israeli claim Syria's regime used chemical weapons, saying it was "serious business" and any evidence had to be weighed carefully.

Warning against a possible rush to judgement, Hagel indicated he had been caught off guard by allegations from an Israeli general this week that Syria had fired chemical agents against rebels in recent months.

Syria's main opposition bloc insisted on Wednesday that any talks between U.S. and Russia on ending their country's war be based on President Bashar Assad's departure.

"According to news sources at the NATO foreign ministers conference in Brussels, U.S. Secretary of State John Kerry and Foreign Minister of Russia Sergei Lavrov met and seemed to share similar views regarding the Syrian crisis," said the National Coalition.

Damascus said on Wednesday it will stop cooperating with international peace envoy Lakhdar Brahimi unless he severs his ties with the Arab League, which it accused of involvement in a conspiracy against Syria.

"Syria has cooperated and will cooperate with Brahimi only as U.N. envoy, because the Arab League is complicit in the conspiracy against Syria," the foreign ministry said in a statement carried by state media.

U.N.-Arab League mediator Lakhdar Brahimi suggested the Security Council consider an arms embargo on both sides of Syria's conflict during a closed-door meeting, a U.N. official said Wednesday.

Brahimi "emphasized the need for a political solution along the lines of the Geneva Communique and warned against the growing militarization and radicalization inside Syria," Under-Secretary-General for Political Affairs Jeffrey Feltman said, describing the address delivered last Friday.

The minaret of Aleppo's ancient Umayyad mosque was destroyed on Wednesday, Syrian state media and a watchdog reported, with the regime and the opposition blaming each other.

An archaeological treasure in Aleppo's UNESCO-listed Old City, the mosque has been the center of fighting for months and had already suffered extensive damage.

Spain backs the formation of a national unity government in Syria as a way out of the country's two-year conflict, its foreign minister said after talks in Beirut on Wednesday.

"The regime of (Syrian President) Bashar Assad has support, more or less, among the population, the Russians and the Iranians, and (can rely) on an army that functions," Jose Manuel Garcia-Margallo said at a meeting with his Lebanese counterpart Adnan Mansour in Beirut.

Syria's main rebel Free Syrian Army on Wednesday rejected calls for jihad (holy war) by Lebanese Islamist clerics.

"Our official position as the Supreme Military Command of the Free Syrian Army... is that we thank them but we reject any calls for jihad in Syria," FSA political and media coordinator Louay Muqdad told Agence France Presse.

President Michel Suleiman called on Wednesday on the Lebanese to abide by the dissociation policy and not to send arms shipments or fighters to the neighboring country Syria.

The president called on different parties not to send “arms shipments and fighters to Syria and not to establish any training bases in Lebanon."

Pope Francis called Wednesday for the release of two Syrian bishops kidnapped by gunmen near Aleppo, after a Christian group appeared to retract its claim that the clerics had been freed.

Aleppo's Greek Orthodox Bishop Boulos Yaziji and Syriac Orthodox Bishop Yohanna Ibrahim were kidnapped on Monday by armed men en route from the Turkish border.