The trilateral summit of Iran, Tajikistan and Afghanistan was held in Tehran on Thursday during which the three parties called for the expansion of cooperation in various areas, Xinhua reported.
Iran's President Mahmoud Ahmadinejad said at the opening ceremony that the three countries' meeting should look for ways to expand relations in view of their situation in the region.
The progress and development of the three states will benefit the entire region, Ahmadinejad said.
He suggested for the use of local currencies of the three countries for the transactions among them as a replacement for foreign currencies.
Tajik President Emomali Rahmon recommended establishing railway between the three countries and linking it to China's railway. The suggestion was welcomed by Ahmadinejad.
Afghan President Hamid Karzai and the Tajik president also called for the expansion of brotherly ties among the three countries which enjoy cultural and historical commonalities.
On Thursday evening, the three countries issued a joint declaration in which they emphasized their points in details.
According to the semi-official Fars news agency, in the declaration, "The three countries urged for the implementation of the previously-agreed documents on transit cooperation and trade and energy developments."
"The declaration also called for the joint campaign against drugs, terrorism and organized crimes."
"The presidents of three countries emphasized, in the declaration, the urgent establishment of joint TV station and upgrading cultural, scientific and educational level of cooperation among the countries."
"The signatory of the declaration announced that they support the peaceful use of nuclear energy as the inalienable right of the Nuclear Non-Proliferation Treaty (NPT) member states."
Afghan and Tajik presidents arrived in Tehran on Thursday morning to attend the summit.
The first tripartite summit took place in Dushanbe in 2006, and the three countries also held their second tripartite talks on the sidelines of Shanghai Summit in 2008.