Yet even as they prepared to step up their own contribution to a war that has killed nearly 100,000 people, they demanded that Iran and Lebanese movement Hizbollah stop supporting President Bashar al-Assad's regime.
Top Qatari diplomat and host Sheikh Hamad bin Jassem al-Thani said a meeting in Doha of foreign ministers of the "Friends of Syria" had taken "secret decisions about practical measures to change the situation on the ground".
A final communique said "each country in its own way" would provide "urgently all the necessary materiel and equipment" so that the rebels could "counter brutal attacks by the regime and its allies and protect the Syrian people."
Sheikh Hamad said two of the 11 countries participating had expressed reservations, with diplomats saying they were Germany and Italy.
Also attending were the foreign ministers of Britain, Egypt, France, Jordan, Saudi Arabia, Turkey, the United Arab Emirates and the United States.
Washington and Doha had called for increasing aid to end what US Secretary of State John Kerry called an "imbalance" in Assad's favour.
Kerry said the United States remained committed to a peace plan that includes a conference in Geneva and a transitional government picked both by Assad and the opposition.
But he said the rebels need more support "for the purpose of being able to get to Geneva and to be able to address the imbalance on the ground".
Sheikh Hamad echoed Kerry's remarks, saying a peaceful end "cannot be reached unless a balance on the ground is achieved, in order to force the regime to sit down to talks."
On Thursday, the rebel Free Syrian Army said it needed anti-aircraft and anti-tank weapons.
A Western diplomat in Doha said on Saturday that FSA chief of staff General Selim Idriss had presented a wish list and that it had been agreed to for the most part.
"Everybody is going to help and help better," the diplomat said, adding that there would be on "important qualitative and quantitative leap".
Later on Saturday, French President Francois Hollande arrived in Qatar for talks with the emir, Sheikh Hamad bin Khalifa al-Thani.
He was expected to highlight the "need for trust, clarity and coordination" in backing the rebels, as Qatar is accused of "supporting Syrian opposition groups it does not know," a French diplomat said.
Meanwhile, French Foreign Minister Laurent Fabius said the ministers demanded that predominantly Shiite Iran and Hizbollah stop meddling in the war by supporting Assad, whose Alawite sect is an offshoot of Shiite Islam.
"We have demanded that Iran and Hizbollah end their intervention in the conflict," said Fabius.
"We are fully against the internationalisation of the conflict," he told reporters.
Kerry also accused Assad of an "internationalisation" of the conflict by bringing in Iran and Hizbollah.
And the final communique said that the entry into Syria of militia and fighters that support the regime, a clear reference to Hizbollah, "must be prevented."
In that respect, they emphasised that neighbouring Iraq and Lebanon need to "actively safeguard their borders in order to ensure that fighters and equipment do not escalate current tensions".
The ministers also warned of the "increasing presence and growing radicalism" and "terrorist elements in Syria."
Western powers have hesitated to arm the rebels for fear weapons would fall into the hands of radical elements among them, such as the powerful Al-Nusra Front, which wants to establish an Islamic state in Syria.
Sheikh Hamad also voiced support for a peace conference but insisted there could be no role in the future government for "Assad and aides with bloodstained hands".
He accused Assad's regime of wanting to block the Geneva conference in order to stay in power, "even if that costs one million dead, millions of displaced and refugees and the destruction of Syria and its partition".
And the final communique stated that Assad "has no role in the transitional governing body or thereafter".
On the ground, loyalist forces pressed a fierce four-day assault on rebel-held parts of Damascus, while insurgents launched a new attack on regime-controlled neighbourhoods of second city Aleppo.
Saturday's developments come as the military pushed on with its bid to end the insurgency in and around Homs in central Syria, said the Syrian Observatory for Human Rights.
They also come a day after at least 100 people were killed nationwide, it added.