Pakistan has emerged as a key mediator between Iran and the United States as the conflict drags on, with Islamabad serving as a go-between for messages passed between the two warring sides.

"Initially, we had planned to hold this meeting in Turkey... However, since our Pakistani counterparts are required to remain in their country, we moved the meeting to Pakistan," Turkish Foreign Minister Hakan Fidan told the private A Haber broadcaster.

"It is possible that we will meet there this weekend," Fidan added.

According to Ankara's top diplomat, the talks would bring together the foreign ministers of the four Muslim-majority countries.

Earlier on Friday, Germany's Foreign Minister Johann Wadephul said he expected a direct US-Iran meeting in Pakistan "very soon", without revealing his source.

While Tehran has refused to admit to holding official talks with Washington, Iran has passed a response to US President Donald Trump's 15-point plan to end the war via Islamabad, according to an anonymous source cited by the Iranian Tasnim press agency.