Foreign Secretary William Hague and his Friends of Syria counterparts have agreed to "provide urgently all the necessary material and equipment" to Syrian rebels opposed to President Bashar al-Assad.
The UK has not committed to supply arms to the Syrian rebels, but each of the group's 11 members will "act in its own way" to support them.
In a communique issued after talks in Qatar, the ministers demanded the withdrawal of Hezbollah militias and fighters from Iran and Iraq who had sided with Assad's regime.
ITV News reporter Martha Fairlie reports:
All military support will be channeled through the Syrian Supreme Military Council, the Friends of Syria said.
The communique also called for fighters supporting Assad to be prevented from crossing into Syria from neighbouring counties.
The foreign ministers also pledged to pursue "all appropriate avenues" at the United Nations to "support and protect the Syrian people".
US Secretary of State John Kerry called for an urgent political resolution to the crisis, saying that unless the bloodshed stops, the region could descend into a chaotic sectarian conflict.
Mr Kerry said, "We're all aiming to achieve a political solution, a political settlement, in Syria but that political settlement will not come about if the opposition can be destroyed by force".
While he offered no specifics, Kerry said the assistance would help change the balance on the battlefield, where regime forces have scored recent victories.
Ministers from Qatar, Saudi Arabia, the United Arab Emirates, Jordan, Egypt, Turkey, Germany, France, and Italy also attended the summit.