The Pakistani Prime Minister, Zafarullah Jamali, has held talks with the Iranian President, Mohammad Khatami, at the start of a three-day visit to Teheran.
The two leaders discussed regional security issues, including Afghanistan, trade issues and plans to lay a gas pipeline from Iran to India through Pakistan.
Mr Jamali stressed before the visit that his focus would be on promoting the two countries' economic relationship.
The Pakistani leader is due to hold talks with Iran's Supreme Leader, Ayatollah Ali Khamenei, during his stay.
From the newsroom of the BBC World Service