The Washington Post reported that U.S. negotiators are expected to raise the issue of American detainees in Iran during upcoming talks in Islamabad on Saturday.

Citing sources familiar with the matter, the report said officials from President Donald Trump’s administration plan to demand the release of U.S. citizens held in Iran as part of the negotiations.

The sources noted that it remains unclear how much pressure Washington will apply on this issue, while other officials suggested the matter could be postponed if the talks encounter difficulties.

The report added that six known American detainees are currently held in Iran.

Islamabad is set to host the talks on Saturday, aimed at reaching a permanent ceasefire agreement between the United States and Iran.