Syrian opposition chief Ahmed Jarba called Saturday for backers of the rebellion to provide it with the "means to fight" the regime, as the conflict entered its fourth year.
In a speech delivered in Istanbul and articles published in the French and US media, Jarba renewed a call for weapons as the rebels take on both President Bashar al-Assad's regime and jihadists.
"Our fighters are not only facing regime forces and their allied gangs," he said in the speech.
"They are also facing extremist gangs and are cleaning our house of terrorist mercenaries, particularly the Islamic State of Iraq and the Levant (ISIL) and others, who sneak up behind the revolutionaries to stab them in the back in the service of the regime."
He said the opposition had agreed to attend peace talks in Geneva earlier this year, but was still waiting for its backers to deliver weapons they pledged before and during the talks.
"We renew our request to the friends of the Syrian people to immediately keep their promises that were made before and during Geneva to do with qualitative weapons," he said.
"We remind them that the time they are trying to buy today will tomorrow be a sword on the neck of the region and peace and security in the world."
Signup to our newsletter and follow us on Facebook and Twitter!
He said the rebels were fighting "mercenaries" from the Lebanese Shiite group Hezbollah, as well as Iraqi and Iranian Shiite fighters.
Hezbollah has acknowledged sending fighters to bolster Assad's troops against the uprising.
In an article attributed to Jarba on the website of French newspaper Le Monde, he said Assad had "failed to crush the revolution" and "would never succeed".
But he also urged the international community to finally provide the military backing to oust the regime.
"The time has come for the free world to help the Syrians to escape their isolation. They should provide the means to fight Bashar al-Assad, and the jihadists that he has done so much to attract."
An English-language version of the article released the previous day made no direct request for military support, a possible reflection of France's greater willingness to engage in military operations in recent years.
France has intervened in Mali and Central African Republic in the past year, and supported direct strikes in Syria last summer following reports that Assad had used chemical weapons.
"Even if the international community (doesn't) have a moral obligation to help the Syrian people, it must act to contain the catastrophe now seeping across every one of Syria's borders, if only for its own interests," the English version concludes.