ISLAMABAD (Reuters) - Pakistani Prime Minister Imran Khan will arrive in Tehran on Saturday, where he will meet Iranian President Hassan Rouhani as part of what is believed to be a mediation effort between Iran and Saudi Arabia.

Pakistani sources said Khan's visit to Tehran was aimed at paving the way for easing tensions between Iran and Saudi Arabia, fueled by conflicts, particularly the one in Yemen for years.

On the sidelines of the UN General Assembly, the Pakistani prime minister said recently that US President Donald Trump and Saudi Crown Prince Mohammed bin Salman had asked him to mediate with Iran to defuse tensions with Saudi Arabia.

The former Iranian diplomat Amir Mousavi told Al-Jazeera that Imran Khan's letter contains, according to leaks and indicators, a clear proposal from Saudi Arabia, specifically from Mohammed bin Salman, to address bilateral relations and regional situations, and end the war in Yemen.

Moussaoui added that Khan would convey bin Salman's vision to Tehran, as well as the Iranian response to Riyadh, which he will visit once his visit to Iran is over.

According to the former Iranian diplomat, there may be an Israeli-American escalation in the region to prevent rapprochement between Iran and Saudi Arabia, and Moussaoui said that targeting the Iranian tanker near the Saudi port of Jeddah could enter into this framework.

Moussaoui said that the issue in this diplomatic movement is to get out of Yemen honorably to Saudi Arabia, adding that US allies realized that Americans can not be relied on in the matter of their security and stability, and that the actions of President Donald Trump proved that, as he put it.

The official IRNA news agency quoted Dawn as saying that Pakistani Prime Minister Imran Khan will hold official talks on Sunday with Rowhani and then head to Riyadh for talks with Saudi officials.

The agency added that official sources in Pakistan confirmed that Khan will go to Tehran to move forward in the initiative of mediation in the region.