Hassan Nasrallah, chief of Lebanon's powerful Shiite Hezbollah movement, criticised US-led strikes against jihadists in Syria on Tuesday, saying he would not back a coalition that served "American interests".
"We have a principle: whether the Americans attack the Islamic State, the Taliban or the former Iraqi regime, we oppose US military intervention, and we are against an international coalition in Syria," he said in a televised address.
"Our position does not change... we refuse all American military intervention, whether its under international cover or that of NATO," he added.
A coalition assembled by Washington to tackle the Islamic State jihadist group began carrying out strikes against the organisation and Al-Qaeda in Syria on Tuesday morning.
Signup to our newsletter and follow us on Facebook and Twitter!
"This coalition, as (US President Barack) Obama said in all his speeches, is intended to defend American interests," Nasrallah said.
"It was only when this (jihadist) danger started to threaten their interests" that Washington responded, he added.
Nasrallah, whose speech was broadcast by Hezbollah's Al-Manar TV, said Lebanon should not be part of the anti-jihadist coalition, though Beirut signed up to the grouping at a meeting this month in Saudi Arabia.
Hezbollah is a key ally of Syria's President Bashar al-Assad and has dispatched fighters to bolster his regime against an uprising that began in 2011.
Nasrallah has defended the group's intervention in Syria by saying it is fighting there to prevent jihadists from entering Lebanon, though the conflict has regularly spilled over into Syria's smaller neighbour.
Syria had warned that any military action taken on its territory without coordination would be an "aggression" but it said Tuesday that Washington had notified it before the air strikes began.