BIRJAND (IRNA) -- Contributing to security and development is a major element of Iran's policy in neighboring Afghanistan, said an Iranian official on Sunday.

Head of Afghanistan's restoration office in Iranian foreign ministry Mohammad-Ebrahim Taherian said during opening of a new customs office on the joint border line adjacent to Farah Province in Southern Khorasan Province in Eastern Iran that during last five years, Iran has implemented 333 development projects in the neighboring country.

Ex-ambassador of Iran to Kabul said on the threshold of Iranian president's visit to Afghanistan, the opening of this customs office is a clear sign of Iran's seriousness and diligence to further expand bilateral ties.

Taherian said that while Iran contributes to development plans and security in Afghanistan, presence of certain countries in this country has caused insecurity for the Afghan people.

The governor of Farah Province Mowlavi Mohieddin Baluch present in the opening ceremony called for more Iranian assistance to implement infrastructure projects in the province and hoped the customs project would strengthen friendly ties between the two Muslim countries.

Southern Khorasan Province has 400 kilometers of joint border with Afghan provinces of Farah and Herat out of the total 940 kilometers of Iran-Afghanistan border line.