Officials said Mottaki met with President Hamid Karzai and other top Afghan officials including Foreign Minister Abdullah Abdullah to discuss bilateral relations and the hundreds of thousands of Afghan refugees living in Iran.
According to Mottaki, Karzai is to visit Iran next month.
Speaking after the signing of the memorandum on cooperation in consular affairs today, Mottaki said about 2,000 Afghans were getting visas to travel to Iran each day.
Afghanistan and Iran share a more than 900-kilometer long border.
An estimated 2.5 million Afghans fled to Iran during the quarter century of war and civil strife that afflicted Afghanistan following the Soviet invasion and occupation in the 1980s.
RFE/RL's World: 2005 In Pictures
A slideshow of images related to the top news stories of 2005 from throughout RFE/RL's broadcast region with links to RFE/RL's reporting.