The United States has begun funneling weapons and technical equipment to rebel fighters in Syria, the Washington Post reported late Wednesday.

Citing U.S. and Syrian sources, the U.S. daily wrote that the CIA had begun delivering shipments of lethal aid in the past fortnight.

Russian President Vladimir Putin warned Wednesday that any U.S. military strike on Syria that circumvents the United Nations would undermine the global body and risk unleashing a wave of terror.

Such military action would "result in more innocent victims and escalation, potentially spreading the conflict far beyond Syria's borders," Putin wrote in an op-ed piece appearing in the New York Times.

A team of U.S. arms experts will accompany Secretary of State John Kerry to Geneva to meet with Russian counterparts for high-stakes talks on Syria's chemical weapons, a U.S. official said Wednesday.

Kerry is set to meet his Russian counterpart Sergei Lavrov first on Thursday, but officials said the talks could stretch into Saturday.

Envoys from Britain, China, France, Russia and the United States -- the permanent veto-wielding members of the U.N. Security Council -- will meet Wednesday to discuss the situation in Syria, diplomats said.

U.N. Secretary General Ban Ki-moon said earlier that the failure to halt atrocities in the war-torn country had become a new stain on the reputation of the world body and the Security Council powers.

A Syrian regime air strike on a field hospital in the northern province of Aleppo killed at least 11 people on Wednesday, the Syrian Observatory for Human Rights said.

"At least 11 people, including a doctor... were killed in an air strike on a field hospital in al-Bab," the Britain-based monitoring group said.

Red Cross chief Peter Maurer on Wednesday urged the international community to do as much to improve the humanitarian situation in Syria as it is doing to fight the chemical weapons threat in the country.

"As much as we appreciate the whole political power and energy going into the really big threat of the use of chemical weapons (in Syria)... we would like to see similar kinds of efforts and energy deployed in order to create circumstances in which humanitarian workers can work," the International Committee of the Red Cross president told reporters in Geneva.

A suicide bombing against a Shiite mosque as worshipers streamed out was the bloodiest of attacks across Iraq that left at least 39 people dead on Wednesday, officials said.

Dozens were wounded in the violence, and locals exacted a grim revenge on one man suspected of being a second attacker in the mosque bombing, which comes amid Iraq's worst bloodshed since 2008.

The Arab League will back a Russian plan to place Syria's chemical weapons under international supervision for eventual destruction, its secretary general said Tuesday.

Nabil al-Arabi told reporters in Cairo the League will "soon issue a statement announcing its support officially" for the Russian plan.

Israeli Prime Minister Benjamin Netanyahu said on Wednesday that the international community must ensure Syria is stripped of its chemical weapons as a lesson to its ally Iran.

Any impression of Syria getting away with its use of such arms would be taken as encouragement by Iran, which Israel and the West accuse of seeking to develop a nuclear arsenal, he said.

Tunisia's National Constituent Assembly on Wednesday partially resumed its activities, which had been suspended since early August due to a political crisis triggered by the assassination of an opposition MP.

The assembly's press service said three parliamentary commissions were called back for the first time since the speaker, Mustapha Ben Jaafar, ordered that their work be halted.