"Air defence systems are necessary for the army to face Israel," Nasrallah told a crowd of thousands of supporters in the eastern town of Baalbek.
"Who can secure these weapons for Lebanon? Vote for the opposition and I will point you in that direction," he said.
Nasrallah criticised the United States, which has supplied nearly $500,000 in training and armaments to the Lebanese army since 2005 but does not provide anti-aircraft defences.
Joe Biden, the US vice-president, said during a visit to Lebanon last week that Washington was committed to meeting the army's needs, but warned that US aid was dependant on the outcome of the election.
Nasrallah also accused Israel of interfering in the elections, repeating his accusation that it was behind a report in Germany's Der Spiegel magazine accusing Hezbollah of involvement in the assassination of Rafiq al-Hariri, a former Lebanese prime minister.
"Why are they scared?" he asked.
"They are scared because a win for the opposition means that the systematic programme of targeting, besieging and isolating the resistance in Lebanon in an attempt to dissolve it, has failed."
Hezbollah has dismissed the Der Spiegel report as being based on "fabrications".
A 34-day war between Hezbollah and Israel in 2006 left more than 1,200 Lebanese and 160 Israelis dead.
The Hezbollah-led coalition is aiming to defeat the March 14 bloc led by Saad al-Hariri, the son of Rafiq, in the parliamentary polls, which are widely believed to be too close to call.