Pakistani Prime Minister Imran Khan began his first official visit to Iran on Sunday for talks set to focus on strengthening ties and countering terrorism, state media reported.
Khan began his two-day visit with a stop in the northeastern holy city of Mashhad, Iran's second largest and home to the shrine of Imam Reza who is revered by Shiite muslims, state television said in a live broadcast.
After visiting the shrine, Khan was to fly to Tehran where on Monday he is expected to hold talks with President Hassan Rouhani and other top officials.
The state-run IRNA news agency said Khan's trip was expected to help "develop ties between the two countries, especially those related to regional cooperation in fighting terrorism and safeguarding borders".
Iran and Pakistan share a long border that runs nears the volatile southeastern province of Sistan-Baluchistan which has witnessed over the years numerous attacks on Iran's security forces.
In March, Rouhani demanded Pakistan act "decisively against anti-Iranian terrorists", following a February attack that killed 27 members of the elite Revolutionary Guards in Sistan-Baluchistan.
Iran has said a Pakistani suicide bomber was behind the attack, which was claimed by the Sunni jihadist group, Jaish al-Adl (Army of Justice), which Tehran says operates mostly out of bases in Pakistan.
Khan's visit to Iran, the first since he took office last year, also comes days after gunmen killed 14 members of Pakistan's security forces in the Balochistan province.
On Saturday Pakistani Foreign Minister Shah Mehmood Qureshi said Islamabad had evidence the "terrorist outfits" that carried out the attack have "training and logistic camps inside Iranian areas bordering Pakistan".
Balochistan, which borders Afghanistan and Iran, is Pakistan's poorest province and the largest by landmass, with Islamist as well as ethnic Baloch separatists active there.