BEIRUT, Lebanon — The leader of Hezbollah, the powerful Lebanese Shiite organization, edged closer on Tuesday to acknowledging that its fighters were battling rebels in neighboring Syria, an intervention that threatens to drag Lebanon deeper into that conflict.

The leader, Hassan Nasrallah, declared in a televised speech that Hezbollah could become more deeply involved in the future, and warned that Syria had “real friends” who would not allow it “to fall into the hands” of America, Israel and Islamic extremists, the forces that the Syrian government routinely blames for the two-year uprising against it.

He appeared to be referring to Iran, a patron of both Hezbollah and the Syrian government, as well as Hezbollah itself, whose well-organized guerrilla fighting force, honed by past battles with the Israeli military in southern Lebanon, is widely considered more effective than Lebanon’s army. Hezbollah relies on Iran and Syria to supply its arms.

“You won’t be able to bring down Damascus and you cannot bring down the regime, militarily,” Mr. Nasrallah said. “The battle will be long.”