Hizbullah's arsenal is a divisive issue in Lebanon, where rival political camps are trying to agree on who should replace pro-Syrian President Emile Lahoud when his term ends on Nov. 23.
Harb, one of two Maronite Christian candidates endorsed by the anti-Syrian majority bloc, told Reuters Lebanon could not continue with a Hizbullah "mini-state inside the state".
The Shi'ite group, which is backed by Syria and Iran, has sworn to use its weapons only against Israel.
Harb said a priority for any new president -- who must be a Maronite in Lebanon's sectarian power-sharing system -- should be to reconvene a national dialogue to discuss how Hizbullah's military power could be brought under state control so that only the government could decide on matters of war and peace.
"Whenever we have a state and government ready to fight for the country's independence, at that moment Hizbullah will not have a pretext to continue having their arms and we'll invite them to be part of the institutions of the state," he added.
Sunni, Druze and Christian factions which command a slim majority in parliament say Hizbullah dragged Lebanon into an unwanted conflict last year by seizing two Israeli soldiers in a cross-border raid to trade for Lebanese held in Israel.
Mistrust between Lebanon's rival camps deepened after the war when Hizbullah accused its Lebanese critics of colluding with Israel's US-backed effort to crush the guerrillas.
Hizbullah, the only Lebanese faction permitted to retain its arms after the 1975-90 civil war, says it needs them to liberate the disputed Shebaa Farms border area and to deter Israel, which withdrew from the south in 2000, from attacking Lebanon again.
But the Islamist group has declared it will not keep its weapons forever and is willing to discuss their future in the context of a national defence strategy for Lebanon.
Harb said the army should be trained, equipped and prepared to defend Lebanon, arguing that it had been unable to function properly during Syria's 29-year military presence, when Damascus called all the shots, including choosing the president.
"The situation now in Lebanon is the result of what happened in the black decades that we had," he said of the era that ended when Syrian troops left in 2005 amid an outcry over the assassination of Lebanese former Prime Minister Rafik al-Hariri.
"Now it's over, it's finished. Now we are asking that the Lebanese people and parliamentarians choose their president and do not accept any interference."
Lebanon's 128-seat parliament is due to meet on Oct. 23 to elect a president after an abortive attempt on Sept. 25.
That failure occurred barely a week after a car bomb killed of MP Antoine Ghanem, the seventh anti-Syrian figure to be slain in Lebanon since Hariri's assassination.
Damascus denies any hand in the killings. A U.N.-led special tribunal is being set up to try anyone who may be indicted.
Harb, a 63-year-old lawyer, said Lebanese-Syrian relations must be recalibrated, with neither country meddling in the other. Ambassadors should be exchanged and borders delineated and controlled to stop flows of illegal arms and terrorists.
"We are asking Syria to respect our sovereignty and we will respect theirs," he said.
Lebanon, often used in the past as a proxy battleground for regional conflicts, wanted no part in any external axis, Harb declared. "We are fed up with this, we paid a very high price and we don't want to continue this in the future."
Harb, in parliament since 1972 with only one four-year break, said Lebanon faced the task of rebuilding the state "from zero" and needed an extraordinary person as president.
Asked why he felt qualified, he said: "I'm stubborn and I believe in my country and in the Lebanese. And I want to ensure the new generation will not suffer like we suffered."