"Lebanon is our friend," Vahidi was quoted as saying by the official IRNA news agency. "If there is a demand in this respect, we are ready to help that country and conduct weapons transactions with it."
In a televised speech on Tuesday, Nasrallah vowed that his Iranian-backed group could help secure the aid for Lebanon's poorly equipped army.
The Hezbollah leader made his suggestion after a U.S. congressman suspended $100 million of American military aid to Lebanon earlier this month over concerns the weapons could be used against Israel and that Hezbollah may have influence over the Lebanese army.
Lebanon's government has since opened an account at the central bank to receive donations to help it purchase weapons for the military.
But Beirut is not entirely dependent on U.S. military assistance, and has turned to other countries, including Russia and Arab nations, for assistance in the past.
Iran is a key supporter of Hezbollah, believed to funnel it weapons and millions of dollars in funding, though Tehran denies arming the Shiite group. Hezbollah, also closely allied to Syria, boasts a heavy arsenal of rockets capable of reaching deep inside Israel.
In Washington, State Department spokesman Mark Toner told reporters the possibility of Iranian arms sales to Lebanon's army underscore "the importance both to our national security and the security of the region to continue with our security assistance to the Lebanese army."
Both the George W. Bush and Obama administrations have backed sending military aid to Lebanon, maintaining that a professional military is critical for the government to exert its sovereign authority, which has been challenged by armed Hezbollah militants.
Asked what the status is of the review of U.S. aid to Lebanon demanded by some in Congress, Toner said: "We're reviewing the program that's under way, and we hope to conclude that soon and renew assistance."