"The Eastern borders of Iran have already been closed to the passage of animals and motor vehicles, yet there are certain areas in Saravan which should be blocked," Ahmadi Moghaddam told reporters on Wednesday.
"Generally speaking, the Eastern borders of the country will be blocked even for passersby by the next three years," he added.
Earlier this month, Iranian Defense Minister Brigadier General Ahmad Vahidi announced that Iran is building a long fence along its border with Pakistan as part of its measures to block the entry of drug-traffickers and terrorists into the country.
Iran is on a crossroad of international drug transit route linking the world drug hub, Afghanistan, to the Persian Gulf and European countries.
Iran spends billions of dollars and has lost thousands of its police troops in the war against traffickers and terrorists.
The crackdown has cost Iran more than 700 million dollars over the past two years. Last year, Iran allocated millions to strengthen border security and block the entry of terrorists and drug traffickers into the country.
Strategies pursued by Tehran include digging canals, building barriers and installing barbed wire to seal its borders.