Hezbollah fighters from Lebanon this week were suspected of playing a role in pro-government attacks on rebel strongholds in Syria. The allegations followed reports small amounts of chemical weapons may have been used during the civil war.
Hague said in a speech before a conference on Syria the conflict was taking a new turn, describing Syria as the top destination for Islamic radicals and making support for coordinated opponents of Syrian President Bashar Assad more necessary now.
"The case for further amendments to the arms embargo on Syria is compelling, in order to increase the pressure on the regime, and to give us the flexibility to respond to continued radicalization and conflict," he told British lawmakers. "We have to be open to every way of strengthening moderates and saving lives rather than the current trajectory of extremism and murder."
Opponents of supporting Syrian rebels through military means are concerned about the possibility of putting weapons in the hands of al-Qaida groups waging war against Assad's regime. Hague stressed that there is no military option available for victory, however.
U.S. Secretary of State John Kerry arrived Wednesday in Jordan ahead of the Syrian peace meeting. Hague said he supported a proposal by Kerry and Russian Foreign Minister Sergei Lavrov for an international dialogue aimed at finding a political solution to the conflict.