JERUSALEM — The president of the International Committee of the Red Cross says Hamas would not allow him access to two Israeli civilians believed to be held by the Islamic militant group in Gaza.

Peter Maurer told reporters Thursday that his organization wants access “to all those detained” in conflict zones it visits. Despite raising the issue, he said he was unable to visit the captive Israelis while in Gaza, where he met with leaders to discuss the strip’s blockade, prisoners held by Israel, and other humanitarian issues.

Hamas, also believed to be holding the remains of two Israeli soldiers killed in a 2014 war, wants Israel to first free 54 Palestinian prisoners re-arrested after release in a 2011 prisoner swap.

Maurer concluded a three-day visit to the region Thursday.