Shaikh Hasan Nasr Allah said on Wednesday that Hizb Allah is protecting Lebanon.
"They want to disarm us for Lebanon to stay defenceless - our force protects Lebanon," Nasr Allah said during a talk show aired on three Lebanese channels, including the resistance movement's Al-Manar TV station.
"The US and Israel have been exerting pressure since 2002 to disarm Hizb Allah. They consider us a major threat for their projects in the region."
On Tuesday, Bush urged the group to give up its weapons and not obstruct the Israeli-Palestinian peace process.
"We view Hizb Allah as a terrorist organisation, and I would hope that Hizb Allah would prove that they're not by laying down arms and not threatening peace," Bush said.
However, US State Department spokesman Adam Ereli did not answer repeated questions about whether Bush was leaving the door open for the group to play a political role in Lebanon.
"We view Hizb Allah as a terrorist organisation, and I would hope that Hizb Allah would prove that they're not by laying down arms and not threatening peace"
US President George Bush
"As with any terrorist organisation, what we're looking for is to get out of the terrorism game," he said.
Hizb Allah rejects the "terrorist" label. It says it is a legitimate resistance organisation which opposes Israel's hegemony in the region.
Nasr Allah says his group does not get orders from Damascus or Tehran to carry out attacks against the Israelis.
But Nasr Allah likened his group to a protective militia.
"If you can convince me that there are other ways to protect Lebanon, I'm ready to listen," he said.
Hizb Allah says it is a legitimate
group resisting Israeli hegemony
"As long as Lebanon remains threatened, even if that lasts a million years, we will say to our children and to their descendants that their patriotic, human, moral and sacred religious duty is to defend their people and their fatherland," he added.
Addressing the anti-Syrian opposition in Lebanon, Nasr Allah stressed that the foreign backing they are receiving has a price "and this price will be the disarming of Hizb Allah".
He also described UN Resolution 1559, which calls for Syria's withdraw from Lebanon as a "resolution to serve the interests of the United States and France".
On the internal scene, he called on the opposition to hold a dialogue and urged a UN-Arab commission to investigate the death of former prime minister Rafiq al-Hariri, who was killed on 14 February in a Beirut bomb blast.
"I suggest we call for an Arab commission to probe into the assassination of Rafik Hariri and let it be discussed in the upcoming Arab summit in Algiers," he said.