Iranian President Ebrahim Raisi arrived in Islamabad on Monday, April 22, on a three-day official visit, the foreign office said.
The visit comes as the two countries seek to mend ties after unprecedented tit-for-tat military strikes this year.
The Iranian president is accompanied by his spouse and a high-level delegation, including the Oil Minister.
Pakistan and Iran highest profile agreement is a stalled gas supply deal signed in 2010 to build a pipeline from Iran's South Pars gas field to Pakistan's southern provinces of Balochistan and Sindh.
Despite Pakistan's dire need of gas, Islamabad has yet to begin construction of its part of the pipeline, citing fears over U.S. sanctions - a concern Tehran has rejected.
Pakistan said it would seek waivers from the U.S., but Washington has said it does not support the project and warned of the risk of sanctions in doing business with Tehran.
Faced with the possibility of contract breach penalties running into the billions of dollars, Islamabad recently gave the go-ahead for construction of an 80-km (50-mile) stretch of the pipeline.