Speaking in a televised speech on Friday, Nasrallah said Hezbullah has been the last party involved in Syria which is marked by massive foreign interference with numerous outsiders who infiltrated the country to fight against it.
"Before us, all groups, Lebanese and non-Lebanese, had already intervened in Syria crisis and had brought in tens of thousands of insurgents to fight in the country," Nasrallah said.
If we had gone to Syria to fight along with the armed insurgents, supporters of the war would say that our fighting was “sacred”, he added.
"We support reforms in Syria but we are totally opposed to destroying the country".
He referred to the 33-day offensive launched by Israel on Lebanon and said that, “One of the most powerful armies in the world was crushed under resistance steps, and yet there are still those who talk about rooting out the resistance”.
Nasrallah also expressed his resistance group’s support for Syria army, saying that "Before Qusayr is the same as after Qusayr. Nothing has changed."
"Isn't the conspiracy the same?... Have the facts changed? On the contrary, the other side is stirring up this conflict even more," Nasrallah said.
"Where we need to be, we will be. Where we began to assume our responsibilities, we will continue to assume our responsibilities," he added.
"To defeat this very, very dangerous conspiracy (against Syria) we will bear any sacrifices and all the consequences."
"The details will depend on the requirements on the ground," Nasrallah said in the address, which came on the Day of the Wounded, honoring Hezbollah casualties from different conflicts.
Nasrallah insisted Hezbollah was against increased sectarian tension in Lebanon, and urged his supporters and others to keep the calm in the country. But he defended the group's intervention in Syria.
"We made the choice and we are involved because we are convinced that our contribution will be effective and it has proven effective," he said, in apparent reference to the freeing of Qusayr.